#+title: The Org Manual
#+subtitle:  Release {{{version}}}
#+author:    The Org Mode Developers
#+language:  en


#+texinfo: @insertcopying

* Introduction
:PROPERTIES:
:DESCRIPTION: Getting started.
:END:
#+cindex: introduction

** Summary
:PROPERTIES:
:DESCRIPTION: Brief summary of what Org does.
:END:
#+cindex: summary

Org Mode is an authoring tool and a TODO lists manager for GNU Emacs.
It relies on a lightweight plain-text markup language used in files
with the =.org= extension.

As an authoring tool, Org helps you write structured documents and
provides exporting facilities. Org files can also be used for literate
programming and reproducible research.  As a TODO lists manager, Org
helps you organize your tasks in a flexible way, from daily needs to
detailed project-planning, allowing logging, multiple views on your
tasks, exporting your agendas, etc.

Org mode is implemented on top of Outline mode, which makes it
possible to keep the content of large files well structured.
Visibility cycling and structure editing help to work with the tree.
Tables are easily created with a built-in table editor.  Plain text
URL-like links connect to websites, emails, Usenet messages, BBDB
entries, and any files related to the projects.

Org develops organizational tasks around notes files that contain
lists or information about projects as plain text.  Project planning
and task management make use of metadata which is part of an outline
node.  Based on this data, specific entries can be extracted in
queries and create dynamic /agenda views/ that also integrate the Emacs
calendar and diary.  Org can be used to implement many different
project planning schemes, such as David Allen's GTD system.

Org files can serve as a single source authoring system with export to
many different formats such as HTML, LaTeX, Open Document, and
Markdown.  New export backends can be derived from existing ones, or
defined from scratch.

Org files can include source code blocks, which makes Org uniquely
suited for authoring technical documents with code examples.  Org
source code blocks are fully functional; they can be evaluated in
place and their results can be captured in the file.  This makes it
possible to create a single file reproducible research compendium.

Org keeps simple things simple.  When first fired up, it should feel
like a straightforward, easy to use outliner.  Complexity is not
imposed, but a large amount of functionality is available when needed.
Org is a toolbox.  Many users actually run only a---very
personal---fraction of Org's capabilities, and know that there is more
whenever they need it.

All of this is achieved with strictly plain text files, the most
portable and future-proof file format.  Org runs in Emacs.  Emacs is
one of the most widely ported programs, so that Org mode is available
on every major platform.

#+cindex: FAQ
There is a website for Org which provides links to the newest version
of Org, as well as additional information, frequently asked questions
(FAQ), links to tutorials, etc.  This page is located at
[[https://orgmode.org]].

#+cindex: print edition
An earlier version (7.3) of this manual was available as a paperback
book from the Network Theory Ltd. publishing company, closed in 2009.

** Installation
:PROPERTIES:
:DESCRIPTION: Installing Org.
:END:
#+cindex: installation

Org is included in distributions of GNU Emacs, you probably do not
need to install it.  Most users will simply activate Org and begin
exploring its features.

If, for one reason or another, you want to install Org on top of this
pre-packaged version, you can use the Emacs package system or clone
Org's git repository.  We *strongly recommend* sticking to a single
installation method.

When installing Org on top of the pre-packaged version, please note
that Org stable versions are meant to be fully compatible with the
last three stable versions of Emacs but not with older Emacsen.

*** Using Emacs packaging system
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Recent Emacs distributions include a packaging system which lets you
install Elisp libraries.  You can install Org from the "package menu",
with {{{kbd(M-x list-packages)}}}.  See [[info:emacs::Package Menu][Package Menu]].

#+attr_texinfo: :tag Important
#+begin_quote
You need to do this in a session where no =.org= file has been
visited, i.e., where no Org built-in function have been loaded.
Otherwise autoload Org functions will mess up the installation.
#+end_quote

*** Using Org's git repository
:PROPERTIES:
:UNNUMBERED: notoc
:END:

You can clone Org's repository and install Org like this:

#+begin_example
$ cd ~/src/
$ git clone https://git.savannah.gnu.org/git/emacs/org-mode.git
$ cd org-mode/
$ make autoloads
#+end_example

Note that in this case, =make autoloads= is mandatory: it defines
Org's version in =org-version.el= and Org's autoloads in
=org-loaddefs.el=.

Make sure you set the load path correctly in your Emacs init file:

#+begin_src emacs-lisp
(add-to-list 'load-path "~/src/org-mode/lisp")
#+end_src

You can also compile with =make=, generate the documentation with
=make doc=, create a local configuration with =make config= and
install Org with =make install=.  Please run =make help= to get the
list of compilation/installation options.

For more detailed explanations on Org's build system, please check the
Org Build System page on [[https://orgmode.org/worg/dev/org-build-system.html][Worg]].

*** Installing Org's contributed packages
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Org's repository used to contain =contrib/= directory for add-ons
contributed by others.  As of Org 9.5, the directory has been moved to
the dedicated org-contrib [[https://git.sr.ht/~bzg/org-contrib][repository]], which you can install
separately as a [[https://elpa.nongnu.org/nongnu/org-contrib.html][package]] from NonGNU ELPA.

There are enough valuable packages maintained outside of the Org repository.
Worg has a list of [[https://orgmode.org/worg/org-contrib/index.html][org-contrib and external packages]], certainly it is not
exhaustive.

** Activation
:PROPERTIES:
:DESCRIPTION: How to activate Org for certain buffers.
:END:
#+cindex: activation
#+cindex: autoload
#+cindex: ELPA
#+cindex: global key bindings
#+cindex: key bindings, global

Org mode buffers need Font Lock to be turned on: this is the default
in Emacs[fn:: If you do not use Font Lock globally turn it on in Org
buffer with =(add-hook 'org-mode-hook #'turn-on-font-lock)=.].

There are compatibility issues between Org mode and some other Elisp
packages (see [[*Packages that conflict with Org mode]]).  Please take the
time to check the list.

#+findex: org-agenda
#+findex: org-capture
#+findex: org-store-link
For a better experience, the three Org commands ~org-store-link~,
~org-capture~ and ~org-agenda~ ought to be accessible anywhere in
Emacs, not just in Org buffers.  To that effect, you need to bind them
to globally available keys, like the ones reserved for users (see
[[info:elisp::Key Binding Conventions]]).  Here are suggested bindings,
please modify the keys to your own liking.

#+begin_src emacs-lisp
(global-set-key (kbd "C-c l") #'org-store-link)
(global-set-key (kbd "C-c a") #'org-agenda)
(global-set-key (kbd "C-c c") #'org-capture)
#+end_src

#+cindex: Org mode, turning on
Files with the =.org= extension use Org mode by default.  To turn on
Org mode in a file that does not have the extension =.org=, make the
first line of a file look like this:

: MY PROJECTS    -*- mode: org; -*-

#+vindex: org-insert-mode-line-in-empty-file
#+texinfo: @noindent
which selects Org mode for this buffer no matter what the file's name
is.  See also the variable ~org-insert-mode-line-in-empty-file~.

Many commands in Org work on the region if the region is /active/.  To
make use of this, you need to have Transient Mark mode turned on,
which is the default.  If you do not like it, you can create an active
region by using the mouse to select a region, or pressing
{{{kbd(C-SPC)}}} twice before moving point.

** Feedback
:PROPERTIES:
:DESCRIPTION: Bug reports, ideas, patches, etc.
:END:
#+cindex: feedback
#+cindex: bug reports
#+cindex: reporting a bug
#+cindex: maintainer
#+cindex: author

If you find problems with Org, or if you have questions, remarks, or
ideas about it, please send an email to the Org mailing list
[[mailto:emacs-orgmode@gnu.org]].  You can subscribe to the list
[[https://lists.gnu.org/mailman/listinfo/emacs-orgmode][from this web
page]].  If you are not a member of the mailing list, your mail will
be passed to the list after a moderator has approved it[fn:: Please
consider subscribing to the mailing list in order to minimize the work
the mailing list moderators have to do.].  We ask you to read and
respect the
[[https://www.gnu.org/philosophy/kind-communication.html][GNU Kind
Communications Guidelines]] when sending messages on this mailing
list.  Please allow up to one month for the response and followup if
no response is received on the bug report.

#+findex: org-version
#+findex: org-submit-bug-report
For bug reports, please first try to reproduce the bug with the latest
version of Org available---if you are running an outdated version, it
is quite possible that the bug has been fixed already.  If the bug
persists, prepare a report and provide as much information as
possible, including the version information of Emacs ({{{kbd(M-x
emacs-version)}}}) and Org ({{{kbd(M-x org-version)}}}), as well as
the Org related setup in the Emacs init file.  The easiest way to do
this is to use the command

: M-x org-submit-bug-report <RET>

#+texinfo: @noindent
which puts all this information into an Emacs mail buffer so that you
only need to add your description.  If you are not sending the Email
from within Emacs, please copy and paste the content into your Email
program.

Sometimes you might face a problem due to an error in your Emacs or
Org mode setup.  Before reporting a bug, it is very helpful to start
Emacs with minimal customizations and reproduce the problem.  Doing so
often helps you determine if the problem is with your customization or
with Org mode itself.  You can start a typical minimal session with
a command like the example below.

: $ emacs -Q -l /path/to/minimal-org.el

However if you are using Org mode as distributed with Emacs, a minimal
setup is not necessary.  In that case it is sufficient to start Emacs
as =emacs -Q=.  The =minimal-org.el= setup file can have contents as
shown below.

#+begin_src emacs-lisp
;;; Minimal setup to load latest `org-mode'.

;; Activate debugging.
(setq debug-on-error t
      debug-on-signal nil
      debug-on-quit nil)

;; Add latest Org mode to load path.
(add-to-list 'load-path (expand-file-name "/path/to/org-mode/lisp"))
#+end_src

If you are using Org mode version from Git repository, you can start
minimal session using make.

: # Bare Emacs
: make repro
: # or pass extra arguments
: make repro REPRO_ARGS="-l /path/to/minimal/config.el /tmp/bug.org"

If an error occurs, a "backtrace" can be very useful---see below on
how to create one.  Often a small example file helps, along with clear
information about:

1. What exactly did you do?
2. What did you expect to happen?
3. What happened instead?

Thank you for helping to improve this program.

*** How to create a useful backtrace
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: backtrace of an error
If working with Org produces an error with a message you do not
understand, you may have hit a bug.  The best way to report this is by
providing, in addition to what was mentioned above, a backtrace.  This
is information from the built-in debugger about where and how the
error occurred.  Here is how to produce a useful backtrace:

1. Reload uncompiled versions of all Org mode Lisp files.  The
   backtrace contains much more information if it is produced with
   uncompiled code.  To do this, use

   : C-u M-x org-reload <RET>

   #+texinfo: @noindent
   or, from the menu: Org \rarr Refresh/Reload \rarr Reload Org uncompiled.

2. Then, activate the debugger:

   : M-x toggle-debug-on-error <RET>

   #+texinfo: @noindent
   or, from the menu: Options \rarr Enter Debugger on Error.

3. Do whatever you have to do to hit the error.  Do not forget to
   document the steps you take.

4. When you hit the error, a =*Backtrace*= buffer appears on the
   screen.  Save this buffer to a file---for example using {{{kbd(C-x
   C-w)}}}---and attach it to your bug report.

** Typesetting Conventions Used in this Manual
:PROPERTIES:
:DESCRIPTION: Typesetting conventions used in this manual.
:ALT_TITLE: Conventions
:END:

*** TODO keywords, tags, properties, etc.
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Org uses various syntactical elements: TODO keywords, tags, property
names, keywords, blocks, etc.  In this manual we use the following
conventions:

#+attr_texinfo: :sep ,
- =TODO=, =WAITING= ::

  TODO keywords are written with all capitals, even if they are
  user-defined.

- =boss=, =ARCHIVE= ::

  Tags are case-sensitive.  User-defined tags are usually written in
  lowercase; built-in tags with special meaning are written as they
  should appear in the document, usually with all capitals.

- =Release=, =PRIORITY= ::

  User-defined properties are capitalized; built-in properties with
  special meaning are written with all capitals.

- =TITLE=, =BEGIN= ... =END= ::

  Keywords and blocks are written in uppercase to enhance their
  readability, but you can use lowercase in your Org files.

*** Key bindings and commands
:PROPERTIES:
:UNNUMBERED: notoc
:END:

The manual lists both the keys and the corresponding commands for
accessing a functionality.  Org mode often uses the same key for
different functions, depending on context.  The command that is bound
to such keys has a generic name, like ~org-metaright~.  In the manual
we will, wherever possible, give the function that is internally
called by the generic command.  For example, in the chapter on
document structure, {{{kbd(M-RIGHT)}}} will be listed to call
~org-do-demote~, while in the chapter on tables, it will be listed to
call ~org-table-move-column-right~.

* Document Structure
:PROPERTIES:
:DESCRIPTION: A tree works like your brain.
:END:

#+cindex: document structure
#+cindex: structure of document
Org is an outliner.  Outlines allow a document to be organized in
a hierarchical structure, which, least for me, is the best
representation of notes and thoughts.  An overview of this structure
is achieved by folding, i.e., hiding large parts of the document to
show only the general document structure and the parts currently being
worked on.  Org greatly simplifies the use of outlines by compressing
the entire show and hide functionalities into a single command,
~org-cycle~, which is bound to the {{{kbd(TAB)}}} key.

** Headlines
:PROPERTIES:
:DESCRIPTION: How to typeset Org tree headlines.
:END:
#+cindex: headlines
#+cindex: outline tree
#+vindex: org-special-ctrl-a/e
#+vindex: org-special-ctrl-k
#+vindex: org-ctrl-k-protect-subtree

Headlines define the structure of an outline tree.  Org headlines
start on the left margin[fn:1] with one or more stars followed by
a space.  For example:

#+begin_example
,* Top level headline
,** Second level
,*** Third level
    some text
,*** Third level
    more text
,* Another top level headline
#+end_example

#+vindex: org-footnote-section
The name defined in ~org-footnote-section~ is reserved.  Do not use it
as a title for your own headings.

Some people find the many stars too noisy and would prefer an outline
that has whitespace followed by a single star as headline starters.
This can be achieved using a Org Indent minor mode.  See [[*A Cleaner
Outline View]] for more information.

Headlines are not numbered.  However, you may want to dynamically
number some, or all, of them.  See [[*Dynamic Headline Numbering]].

#+vindex: org-cycle-separator-lines
An empty line after the end of a subtree is considered part of it and
is hidden when the subtree is folded.  However, if you leave at least
two empty lines, one empty line remains visible after folding the
subtree, in order to structure the collapsed view.  See the variable
~org-cycle-separator-lines~ to modify this behavior.

** Visibility Cycling
:PROPERTIES:
:DESCRIPTION: Show and hide, much simplified.
:END:
#+cindex: cycling, visibility
#+cindex: visibility cycling
#+cindex: trees, visibility
#+cindex: show hidden text
#+cindex: hide text

*** Global and local cycling
:PROPERTIES:
:DESCRIPTION: Cycling through various visibility states.
:END:
#+cindex: subtree visibility states
#+cindex: subtree cycling
#+cindex: folded, subtree visibility state
#+cindex: children, subtree visibility state
#+cindex: subtree, subtree visibility state

Outlines make it possible to hide parts of the text in the buffer.
Org uses just two commands, bound to {{{kbd(TAB)}}} and
{{{kbd(S-TAB)}}} to change the visibility in the buffer.

#+attr_texinfo: :sep ,
- {{{kbd(TAB)}}} (~org-cycle~) ::

  #+kindex: TAB
  #+findex: org-cycle
  /Subtree cycling/: Rotate current subtree among the states

  #+begin_example
  ,-> FOLDED -> CHILDREN -> SUBTREE --.
  '-----------------------------------'
  #+end_example

  #+vindex: org-cycle-emulate-tab
  Point must be on a headline for this to work[fn:: See, however, the
  option ~org-cycle-emulate-tab~.].

- {{{kbd(S-TAB)}}} (~org-global-cycle~), {{{kbd(C-u TAB)}}} ::

  #+cindex: global visibility states
  #+cindex: global cycling
  #+cindex: overview, global visibility state
  #+cindex: contents, global visibility state
  #+cindex: show all, global visibility state
  #+kindex: C-u TAB
  #+kindex: S-TAB
  #+findex: org-global-cycle
  /Global cycling/: Rotate the entire buffer among the states

  #+begin_example
  ,-> OVERVIEW -> CONTENTS -> SHOW ALL --.
  '--------------------------------------'
  #+end_example

  When {{{kbd(S-TAB)}}} is called with a numeric prefix argument
  {{{var(N)}}}, view contents only up to headlines of level
  {{{var(N)}}}.

  Note that inside tables (see [[*Tables]]), {{{kbd(S-TAB)}}} jumps to the
  previous field instead.

  #+vindex: org-cycle-global-at-bob
  You can run global cycling using {{{kbd(TAB)}}} only if point is at
  the very beginning of the buffer, but not on a headline, and
  ~org-cycle-global-at-bob~ is set to a non-~nil~ value.

- {{{kbd(C-u C-u TAB)}}} (~org-set-startup-visibility~) ::

  #+cindex: startup visibility
  #+kindex: C-u C-u TAB
  #+findex: org-set-startup-visibility
  Switch back to the startup visibility of the buffer (see [[*Initial
  visibility]]).

- {{{kbd(C-u C-u C-u TAB)}}} (~org-show-all~) ::

  #+cindex: show all, command
  #+kindex: C-u C-u C-u TAB
  #+findex: org-show-all
  Show all, including drawers.

- {{{kbd(C-c C-r)}}} (~org-reveal~) ::

  #+cindex: revealing context
  #+kindex: C-c C-r
  #+findex: org-reveal
  Reveal context around point, showing the current entry, the
  following heading and the hierarchy above.  It is useful for working
  near a location that has been exposed by a sparse tree command (see
  [[*Sparse Trees]]) or an agenda command (see [[*Commands in the Agenda
  Buffer]]).  With a prefix argument, show, on each level, all sibling
  headings.  With a double prefix argument, also show the entire
  subtree of the parent.

- {{{kbd(C-c C-k)}}} (~org-show-branches~) ::

  #+cindex: show branches, command
  #+kindex: C-c C-k
  #+findex: org-show-branches
  Expose all the headings of the subtree, but not their bodies.

- {{{kbd(C-c TAB)}}} (~org-show-children~) ::

  #+cindex: show children, command
  #+kindex: C-c TAB
  #+findex: org-show-children
  Expose all direct children of the subtree.  With a numeric prefix
  argument {{{var(N)}}}, expose all children down to level
  {{{var(N)}}}.

- {{{kbd(C-c C-x b)}}} (~org-tree-to-indirect-buffer~) ::

  #+kindex: C-c C-x b
  #+findex: org-tree-to-indirect-buffer
  Show the current subtree in an indirect buffer[fn:2].  With
  a numeric prefix argument {{{var(N)}}}, go up to level {{{var(N)}}}
  and then take that tree.  If {{{var(N)}}} is negative then go up
  that many levels.  With a {{{kbd(C-u)}}} prefix, do not remove the
  previously used indirect buffer.

- {{{kbd(C-c C-x v)}}} (~org-copy-visible~) ::

  #+kindex: C-c C-x v
  #+findex: org-copy-visible
  Copy the /visible/ text in the region into the kill ring.

*** Initial visibility
:PROPERTIES:
:DESCRIPTION: Setting the initial visibility state.
:END:

#+vindex: org-startup-folded
When Emacs first visits an Org file, the global state is set to
~showeverything~, i.e., all file content is visible[fn:: When
~org-agenda-inhibit-startup~ is non-~nil~, Org does not honor the
default visibility state when first opening a file for the agenda (see
[[*Speeding Up Your Agendas]]).].  This can be configured through the
variable ~org-startup-folded~, or on a per-file basis by adding one of
the following lines anywhere in the buffer:

#+cindex: @samp{STARTUP}, keyword
#+begin_example
,#+STARTUP: overview
,#+STARTUP: content
,#+STARTUP: showall
,#+STARTUP: show2levels
,#+STARTUP: show3levels
,#+STARTUP: show4levels
,#+STARTUP: show5levels
,#+STARTUP: showeverything
#+end_example

#+cindex: @samp{VISIBILITY}, property
Furthermore, any entries with a =VISIBILITY= property (see [[*Properties
and Columns]]) get their visibility adapted accordingly.  Allowed values
for this property are =folded=, =children=, =content=, and =all=.

- {{{kbd(C-u C-u TAB)}}} (~org-set-startup-visibility~) ::

  #+kindex: C-u C-u TAB
  #+findex: org-set-startup-visibility
  Switch back to the startup visibility of the buffer, i.e., whatever
  is requested by startup options and =VISIBILITY= properties in
  individual entries.

*** Catching invisible edits
:PROPERTIES:
:DESCRIPTION: Preventing mistakes when editing invisible parts.
:END:
#+cindex: edits, catching invisible

#+vindex: org-fold-catch-invisible-edits
Sometimes you may inadvertently edit an invisible part of the buffer
and be confused on what has been edited and how to undo the mistake.
Setting ~org-fold-catch-invisible-edits~ to non-~nil~ helps preventing
this.  See the docstring of this option on how Org should catch
invisible edits and process them.

** Motion
:PROPERTIES:
:DESCRIPTION: Jumping to other headlines.
:END:
#+cindex: motion, between headlines
#+cindex: jumping, to headlines
#+cindex: headline navigation

The following commands jump to other headlines in the buffer.

- {{{kbd(C-c C-n)}}} (~org-next-visible-heading~) ::

  #+kindex: C-c C-n
  #+findex: org-next-visible-heading
  Next heading.

- {{{kbd(C-c C-p)}}} (~org-previous-visible-heading~) ::

  #+kindex: C-c C-p
  #+findex: org-previous-visible-heading
  Previous heading.

- {{{kbd(C-c C-f)}}} (~org-forward-heading-same-level~) ::

  #+kindex: C-c C-f
  #+findex: org-forward-heading-same-level
  Next heading same level.

- {{{kbd(C-c C-b)}}} (~org-backward-heading-same-level~) ::

  #+kindex: C-c C-b
  #+findex: org-backward-heading-same-level
  Previous heading same level.

- {{{kbd(C-c C-u)}}} (~outline-up-heading~) ::

  #+kindex: C-c C-u
  #+findex: outline-up-heading
  Backward to higher level heading.

- {{{kbd(C-c C-j)}}} (~org-goto~) ::

  #+kindex: C-c C-j
  #+findex: org-goto
  #+vindex: org-goto-auto-isearch
  Jump to a different place without changing the current outline
  visibility.  Shows the document structure in a temporary buffer,
  where you can use the following keys to find your destination:

  #+attr_texinfo: :columns 0.3 0.7
  | {{{kbd(TAB)}}}            | Cycle visibility.               |
  | {{{kbd(DOWN)}}} / {{{kbd(UP)}}} | Next/previous visible headline. |
  | {{{kbd(RET)}}}            | Select this location.           |
  | {{{kbd(/)}}}              | Do a Sparse-tree search         |

  #+texinfo: @noindent
  The following keys work if you turn off ~org-goto-auto-isearch~

  #+attr_texinfo: :columns 0.3 0.7
  | {{{kbd(n)}}} / {{{kbd(p)}}}   | Next/previous visible headline.    |
  | {{{kbd(f)}}} / {{{kbd(b)}}}   | Next/previous headline same level. |
  | {{{kbd(u)}}}            | One level up.                      |
  | {{{kbd(0)}}} ... {{{kbd(9)}}} | Digit argument.                    |
  | {{{kbd(q)}}}            | Quit.                              |

  #+vindex: org-goto-interface
  #+texinfo: @noindent
  See also the variable ~org-goto-interface~.

** Structure Editing
:PROPERTIES:
:DESCRIPTION: Changing sequence and level of headlines.
:END:
#+cindex: structure editing
#+cindex: headline, promotion and demotion
#+cindex: promotion, of subtrees
#+cindex: demotion, of subtrees
#+cindex: subtree, cut and paste
#+cindex: pasting, of subtrees
#+cindex: cutting, of subtrees
#+cindex: copying, of subtrees
#+cindex: sorting, of subtrees
#+cindex: subtrees, cut and paste

#+attr_texinfo: :sep ,
- {{{kbd(M-RET)}}} (~org-meta-return~) ::

  #+kindex: M-RET
  #+findex: org-meta-return
  #+vindex: org-M-RET-may-split-line
  Insert a new heading, item or row.

  If the command is used at the /beginning/ of a line, and if there is
  a heading or a plain list item (see [[*Plain Lists]]) at point, the new
  heading/item is created /before/ the current line.  When used at the
  beginning of a regular line of text, turn that line into a heading.

  When this command is used in the middle of a line, the line is split
  and the rest of the line becomes the new item or headline.  If you
  do not want the line to be split, customize
  ~org-M-RET-may-split-line~.

  Calling the command with a {{{kbd(C-u)}}} prefix unconditionally
  inserts a new heading at the end of the current subtree, thus
  preserving its contents.  With a double {{{kbd(C-u C-u)}}} prefix,
  the new heading is created at the end of the parent subtree instead.

- {{{kbd(C-RET)}}} (~org-insert-heading-respect-content~) ::

  #+kindex: C-RET
  #+findex: org-insert-heading-respect-content
  Insert a new heading at the end of the current subtree.

- {{{kbd(M-S-RET)}}} (~org-insert-todo-heading~) ::

  #+kindex: M-S-RET
  #+findex: org-insert-todo-heading
  #+vindex: org-treat-insert-todo-heading-as-state-change
  Insert new TODO entry with same level as current heading.  See also
  the variable ~org-treat-insert-todo-heading-as-state-change~.

- {{{kbd(C-S-RET)}}} (~org-insert-todo-heading-respect-content~) ::

  #+kindex: C-S-RET
  #+findex: org-insert-todo-heading-respect-content
  Insert new TODO entry with same level as current heading.  Like
  {{{kbd(C-RET)}}}, the new headline is inserted after the current
  subtree.

- {{{kbd(TAB)}}} (~org-cycle~) ::

  #+kindex: TAB
  #+findex: org-cycle
  In a new entry with no text yet, the first {{{kbd(TAB)}}} demotes
  the entry to become a child of the previous one.  The next
  {{{kbd(TAB)}}} makes it a parent, and so on, all the way to top
  level.  Yet another {{{kbd(TAB)}}}, and you are back to the initial
  level.

- {{{kbd(M-LEFT)}}} (~org-do-promote~), {{{kbd(M-RIGHT)}}} (~org-do-demote~) ::

  #+kindex: M-LEFT
  #+findex: org-do-promote
  #+kindex: M-RIGHT
  #+findex: org-do-demote
  Promote or demote current heading by one level.

  #+cindex: region, active
  #+cindex: active region
  #+cindex: transient mark mode
  When there is an active region---i.e., when Transient Mark mode is
  active---promotion and demotion work on all headlines in the region.
  To select a region of headlines, it is best to place both point and
  mark at the beginning of a line, mark at the beginning of the first
  headline, and point at the line just after the last headline to
  change.

- {{{kbd(M-S-LEFT)}}} (~org-promote-subtree~) ::

  #+kindex: M-S-LEFT
  #+findex: org-promote-subtree
  Promote the current subtree by one level.

- {{{kbd(M-S-RIGHT)}}} (~org-demote-subtree~) ::

  #+kindex: M-S-RIGHT
  #+findex: org-demote-subtree
  Demote the current subtree by one level.

- {{{kbd(M-UP)}}} (~org-move-subtree-up~) ::

  #+kindex: M-UP
  #+findex: org-move-subtree-up
  Move subtree up, i.e., swap with previous subtree of same level.

- {{{kbd(M-DOWN)}}} (~org-move-subtree-down~) ::

  #+kindex: M-DOWN
  #+findex: org-move-subtree-down
  Move subtree down, i.e., swap with next subtree of same level.

- {{{kbd(C-c @)}}} (~org-mark-subtree~) ::

  #+kindex: C-c @@
  #+findex: org-mark-subtree
  Mark the subtree at point.  Hitting repeatedly marks subsequent
  subtrees of the same level as the marked subtree.

- {{{kbd(C-c C-x C-w)}}} (~org-cut-subtree~) ::

  #+kindex: C-c C-x C-w
  #+findex: org-cut-subtree
  Kill subtree, i.e., remove it from buffer but save in kill ring.
  With a numeric prefix argument N, kill N sequential subtrees.

- {{{kbd(C-c C-x M-w)}}} (~org-copy-subtree~) ::

  #+kindex: C-c C-x M-w
  #+findex: org-copy-subtree
  Copy subtree to kill ring.  With a numeric prefix argument N, copy
  the N sequential subtrees.

- {{{kbd(C-c C-x C-y)}}} (~org-paste-subtree~) ::

  #+kindex: C-c C-x C-y
  #+findex: org-paste-subtree
  Yank subtree from kill ring.  This does modify the level of the
  subtree to make sure the tree fits in nicely at the yank position.
  The yank level can also be specified with a numeric prefix argument,
  or by yanking after a headline marker like =****=.

- {{{kbd(C-y)}}} (~org-yank~) ::

  #+kindex: C-y
  #+findex: org-yank
  #+vindex: org-yank-adjusted-subtrees
  #+vindex: org-yank-folded-subtrees
  Depending on the variables ~org-yank-adjusted-subtrees~ and
  ~org-yank-folded-subtrees~, Org's internal ~yank~ command pastes
  subtrees folded and in a clever way, using the same command as
  {{{kbd(C-c C-x C-y)}}}.  With the default settings, no level
  adjustment takes place, but the yanked tree is folded unless doing
  so would swallow text previously visible.  Any prefix argument to
  this command forces a normal ~yank~ to be executed, with the prefix
  passed along.  A good way to force a normal yank is {{{kbd(C-u
  C-y)}}}.  If you use ~yank-pop~ after a yank, it yanks previous kill
  items plainly, without adjustment and folding.

- {{{kbd(C-c C-x c)}}} (~org-clone-subtree-with-time-shift~) ::

  #+kindex: C-c C-x c
  #+findex: org-clone-subtree-with-time-shift
  Clone a subtree by making a number of sibling copies of it.  You are
  prompted for the number of copies to make, and you can also specify
  if any timestamps in the entry should be shifted.  This can be
  useful, for example, to create a number of tasks related to a series
  of lectures to prepare.  For more details, see the docstring of the
  command ~org-clone-subtree-with-time-shift~.

- {{{kbd(C-c C-w)}}} (~org-refile~) ::

  #+kindex: C-c C-w
  #+findex: org-refile
  Refile entry or region to a different location.  See [[*Refile and
  Copy]].

- {{{kbd(C-c ^)}}} (~org-sort~) ::

  #+kindex: C-c ^
  #+findex: org-sort
  Sort same-level entries.  When there is an active region, all
  entries in the region are sorted.  Otherwise the children of the
  current headline are sorted.  The command prompts for the sorting
  method, which can be alphabetically, numerically, by time---first
  timestamp with active preferred, creation time, scheduled time,
  deadline time---by priority, by TODO keyword---in the sequence the
  keywords have been defined in the setup---or by the value of
  a property.  Reverse sorting is possible as well.  You can also
  supply your own function to extract the sorting key.  With
  a {{{kbd(C-u)}}} prefix, sorting is case-sensitive.

- {{{kbd(C-x n s)}}} (~org-narrow-to-subtree~) ::

  #+kindex: C-x n s
  #+findex: org-narrow-to-subtree
  Narrow buffer to current subtree.

- {{{kbd(C-x n b)}}} (~org-narrow-to-block~) ::

  #+kindex: C-x n b
  #+findex: org-narrow-to-block
  Narrow buffer to current block.

- {{{kbd(C-x n w)}}} (~widen~) ::

  #+kindex: C-x n w
  #+findex: widen
  Widen buffer to remove narrowing.

- {{{kbd(C-c *)}}} (~org-toggle-heading~) ::

  #+kindex: C-c *
  #+findex: org-toggle-heading
  Turn a normal line or plain list item into a headline---so that it
  becomes a subheading at its location.  Also turn a headline into
  a normal line by removing the stars.  If there is an active region,
  turn all lines in the region into headlines.  If the first line in
  the region was an item, turn only the item lines into headlines.
  Finally, if the first line is a headline, remove the stars from all
  headlines in the region.

Note that when point is inside a table (see [[*Tables]]), the Meta-Cursor
keys have different functionality.

** Sparse Trees
:PROPERTIES:
:DESCRIPTION: Matches embedded in context.
:END:
#+cindex: sparse trees
#+cindex: trees, sparse
#+cindex: folding, sparse trees
#+cindex: occur, command

#+vindex: org-show-context-detail
An important feature of Org mode is the ability to construct /sparse
trees/ for selected information in an outline tree, so that the entire
document is folded as much as possible, but the selected information
is made visible along with the headline structure above it[fn:: See
also the variable ~org-show-context-detail~ to decide how much context
is shown around each match.].  Just try it out and you will see
immediately how it works.

Org mode contains several commands creating such trees, all these
commands can be accessed through a dispatcher:

- {{{kbd(C-c /)}}} (~org-sparse-tree~) ::

  #+kindex: C-c /
  #+findex: org-sparse-tree
  This prompts for an extra key to select a sparse-tree creating
  command.

- {{{kbd(C-c / r)}}} or {{{kbd(C-c / /)}}} (~org-occur~) ::

  #+kindex: C-c / r
  #+kindex: C-c / /
  #+findex: org-occur
  #+vindex: org-remove-highlights-with-change
  Prompts for a regexp (see [[*Regular Expressions]]) and shows a
  sparse tree with all matches.  If the match is in a headline, the
  headline is made visible.  If the match is in the body of an entry,
  headline and body are made visible.  In order to provide minimal
  context, also the full hierarchy of headlines above the match is
  shown, as well as the headline following the match.  Each match is
  also highlighted; the highlights disappear when the buffer is
  changed by an editing command, or by pressing {{{kbd(C-c
  C-c)}}}[fn:: This depends on the option
  ~org-remove-highlights-with-change~.].  When called with a
  {{{kbd(C-u)}}} prefix argument, previous highlights are kept, so
  several calls to this command can be stacked.

- {{{kbd(M-g n)}}} or {{{kbd(M-g M-n)}}} (~next-error~) ::

  #+kindex: M-g n
  #+kindex: M-g M-n
  #+findex: next-error
  Jump to the next sparse tree match in this buffer.

- {{{kbd(M-g p)}}} or {{{kbd(M-g M-p)}}} (~previous-error~) ::

  #+kindex: M-g p
  #+kindex: M-g M-p
  #+findex: previous-error
  Jump to the previous sparse tree match in this buffer.

#+vindex: org-agenda-custom-commands
For frequently used sparse trees of specific search strings, you can
use the variable ~org-agenda-custom-commands~ to define fast keyboard
access to specific sparse trees.  These commands will then be
accessible through the agenda dispatcher (see [[*The Agenda Dispatcher]]).
For example:

#+begin_src emacs-lisp
(setq org-agenda-custom-commands
      '(("f" occur-tree "FIXME")))
#+end_src

#+texinfo: @noindent
defines the key {{{kbd(f)}}} as a shortcut for creating a sparse tree
matching the string =FIXME=.

The other sparse tree commands select headings based on TODO keywords,
tags, or properties and are discussed later in this manual.

#+kindex: C-c C-e C-v
#+cindex: printing sparse trees
#+cindex: visible text, printing
To print a sparse tree, you can use the Emacs command
~ps-print-buffer-with-faces~ which does not print invisible parts of
the document.  Or you can use the command {{{kbd(C-c C-e C-v)}}} to
export only the visible part of the document and print the resulting
file.

** Plain Lists
:PROPERTIES:
:DESCRIPTION: Additional structure within an entry.
:END:
#+cindex: plain lists
#+cindex: lists, plain
#+cindex: lists, ordered
#+cindex: ordered lists

Within an entry of the outline tree, hand-formatted lists can provide
additional structure.  They also provide a way to create lists of
checkboxes (see [[*Checkboxes]]).  Org supports editing such lists, and
every exporter (see [[*Exporting]]) can parse and format them.

Org knows ordered lists, unordered lists, and description lists.

#+attr_texinfo: :indic @bullet
- /Unordered/ list items start with =-=, =+=, or =*=[fn:3] as bullets.

-
  #+vindex: org-plain-list-ordered-item-terminator
  #+vindex: org-alphabetical-lists
  /Ordered/ list items start with a numeral followed by either a
  period or a right parenthesis[fn:: You can filter out any of them by
  configuring ~org-plain-list-ordered-item-terminator~.], such as =1.=
  or =1)=[fn:4] If you want a list to start with a different
  value---e.g., 20---start the text of the item with =[@20]=[fn:5].
  Those constructs can be used in any item of the list in order to
  enforce a particular numbering.

- /Description/ list items are unordered list items, and contain the
  separator =::= to distinguish the description /term/ from the
  description.

Items belonging to the same list must have the same indentation on the
first line.  In particular, if an ordered list reaches number =10.=,
then the 2-digit numbers must be written left-aligned with the other
numbers in the list.  An item ends before the next line that is less
or equally indented than its bullet/number.

A list ends whenever every item has ended, which means before any line
less or equally indented than items at top level.  It also ends before
two blank lines.  In that case, all items are closed.  Here is an
example:

#+begin_example
,* Lord of the Rings
My favorite scenes are (in this order)
1. The attack of the Rohirrim
2. Eowyn's fight with the witch king
   + this was already my favorite scene in the book
   + I really like Miranda Otto.
3. Peter Jackson being shot by Legolas
   - on DVD only
   He makes a really funny face when it happens.
But in the end, no individual scenes matter but the film as a whole.
Important actors in this film are:
- Elijah Wood :: He plays Frodo
- Sean Astin :: He plays Sam, Frodo's friend.  I still remember him
     very well from his role as Mikey Walsh in /The Goonies/.
#+end_example

Org supports these lists by tuning filling and wrapping commands to
deal with them correctly, and by exporting them properly (see
[[*Exporting]]).  Since indentation is what governs the structure of these
lists, many structural constructs like =#+BEGIN_= blocks can be
indented to signal that they belong to a particular item.

#+vindex: org-list-demote-modify-bullet
#+vindex: org-list-indent-offset
If you find that using a different bullet for a sub-list---than that
used for the current list-level---improves readability, customize the
variable ~org-list-demote-modify-bullet~.  To get a greater difference
of indentation between items and theirs sub-items, customize
~org-list-indent-offset~.

#+vindex: org-list-automatic-rules
The following commands act on items when point is in the first line of
an item---the line with the bullet or number.  Some of them imply the
application of automatic rules to keep list structure intact.  If some
of these actions get in your way, configure ~org-list-automatic-rules~
to disable them individually.

#+attr_texinfo: :sep ,
- {{{kbd(TAB)}}} (~org-cycle~) ::

  #+cindex: cycling, in plain lists
  #+kindex: TAB
  #+findex: org-cycle
  #+vindex: org-cycle-include-plain-lists
  Items can be folded just like headline levels.  Normally this works
  only if point is on a plain list item.  For more details, see the
  variable ~org-cycle-include-plain-lists~.  If this variable is set
  to ~integrate~, plain list items are treated like low-level
  headlines.  The level of an item is then given by the indentation of
  the bullet/number.  Items are always subordinate to real headlines,
  however; the hierarchies remain completely separated.  In a new item
  with no text yet, the first {{{kbd(TAB)}}} demotes the item to
  become a child of the previous one.  Subsequent {{{kbd(TAB)}}}s move
  the item to meaningful levels in the list and eventually get it back
  to its initial position.

- {{{kbd(M-RET)}}} (~org-insert-heading~) ::

  #+kindex: M-RET
  #+findex: org-insert-heading
  #+vindex: org-M-RET-may-split-line
  Insert new item at current level.  With a prefix argument, force a
  new heading (see [[*Structure Editing]]).  If this command is used
  in the middle of an item, that item is /split/ in two, and the
  second part becomes the new item[fn:: If you do not want the item to
  be split, customize the variable ~org-M-RET-may-split-line~.].  If
  this command is executed /before item's body/, the new item is
  created /before/ the current one.

- {{{kbd(M-S-RET)}}} ::

  #+kindex: M-S-RET
  Insert a new item with a checkbox (see [[*Checkboxes]]).

- {{{kbd(S-UP)}}}, {{{kbd(S-DOWN)}}} ::

  #+kindex: S-UP
  #+kindex: S-DOWN
  #+cindex: shift-selection-mode
  #+vindex: org-support-shift-select
  #+vindex: org-list-use-circular-motion
  Jump to the previous/next item in the current list, but only if
  ~org-support-shift-select~ is off[fn:: If you want to cycle around
  items that way, you may customize ~org-list-use-circular-motion~.].
  If not, you can still use paragraph jumping commands like
  {{{kbd(C-UP)}}} and {{{kbd(C-DOWN)}}} to quite similar effect.

- {{{kbd(M-UP)}}}, {{{kbd(M-DOWN)}}} ::

  #+kindex: M-UP
  #+kindex: M-DOWN
  Move the item including subitems up/down[fn:: See
  ~org-list-use-circular-motion~ for a cyclic behavior.], i.e., swap
  with previous/next item of same indentation.  If the list is
  ordered, renumbering is automatic.

- {{{kbd(M-LEFT)}}}, {{{kbd(M-RIGHT)}}} ::

  #+kindex: M-LEFT
  #+kindex: M-RIGHT
  Decrease/increase the indentation of an item, leaving children
  alone.

- {{{kbd(M-S-LEFT)}}}, {{{kbd(M-S-RIGHT)}}} ::

  #+kindex: M-S-LEFT
  #+kindex: M-S-RIGHT
  Decrease/increase the indentation of the item, including subitems.
  Initially, the item tree is selected based on current indentation.
  When these commands are executed several times in direct succession,
  the initially selected region is used, even if the new indentation
  would imply a different hierarchy.  To use the new hierarchy, break
  the command chain by moving point.

  As a special case, using this command on the very first item of
  a list moves the whole list.  This behavior can be disabled by
  configuring ~org-list-automatic-rules~.  The global indentation of
  a list has no influence on the text /after/ the list.

- {{{kbd(C-c C-c)}}} ::

  #+kindex: C-c C-c
  If there is a checkbox (see [[*Checkboxes]]) in the item line, toggle
  the state of the checkbox.  In any case, verify bullets and
  indentation consistency in the whole list.

- {{{kbd(C-c -)}}} ::

  #+kindex: C-c -
  #+vindex: org-plain-list-ordered-item-terminator
  Cycle the entire list level through the different itemize/enumerate
  bullets (=-=, =+=, =*=, =1.=, =1)=) or a subset of them, depending
  on ~org-plain-list-ordered-item-terminator~, the type of list, and
  its indentation.  With a numeric prefix argument N, select the Nth
  bullet from this list.  If there is an active region when calling
  this, all lines are converted to list items.  With a prefix
  argument, the selected text is changed into a single item.  If the
  first line already was a list item, any item marker is removed from
  the list.  Finally, even without an active region, a normal line is
  converted into a list item.

- {{{kbd(C-c *)}}} ::

  #+kindex: C-c *
  Turn a plain list item into a headline---so that it becomes
  a subheading at its location.  See [[*Structure Editing]], for
  a detailed explanation.

- {{{kbd(C-c C-*)}}} ::

  #+kindex: C-c C-*
  Turn the whole plain list into a subtree of the current heading.
  Checkboxes (see [[*Checkboxes]]) become =TODO=, respectively =DONE=,
  keywords when unchecked, respectively checked.

- {{{kbd(S-LEFT)}}}, {{{kbd(S-RIGHT)}}} ::

  #+vindex: org-support-shift-select
  #+kindex: S-LEFT
  #+kindex: S-RIGHT
  This command also cycles bullet styles when point is in on the
  bullet or anywhere in an item line, details depending on
  ~org-support-shift-select~.

- {{{kbd(C-c ^)}}} ::

  #+kindex: C-c ^
  #+cindex: sorting, of plain list
  Sort the plain list.  Prompt for the sorting method: numerically,
  alphabetically, by time, or by custom function.

** Drawers
:PROPERTIES:
:DESCRIPTION: Tucking stuff away.
:END:
#+cindex: drawers
#+cindex: visibility cycling, drawers

Sometimes you want to keep information associated with an entry, but
you normally do not want to see it.  For this, Org mode has /drawers/.
They can contain anything but a headline and another drawer.  Drawers
look like this:

#+begin_example
,** This is a headline
Still outside the drawer
:DRAWERNAME:
This is inside the drawer.
:END:
After the drawer.
#+end_example

#+kindex: C-c C-x d
#+findex: org-insert-drawer
You can interactively insert a drawer at point by calling
~org-insert-drawer~, which is bound to {{{kbd(C-c C-x d)}}}.  With an
active region, this command puts the region inside the drawer.  With a
prefix argument, this command calls non-interactive function
~org-insert-property-drawer~, which creates a =PROPERTIES= drawer
right below the current headline.  Org mode uses this special drawer
for storing properties (see [[*Properties and Columns]]).  You cannot use
it for anything else.

Completion over drawer keywords is also possible using
{{{kbd(M-TAB)}}}[fn:6].

Visibility cycling (see [[*Visibility Cycling]]) on the headline hides and
shows the entry, but keep the drawer collapsed to a single line.  In
order to look inside the drawer, you need to move point to the drawer
line and press {{{kbd(TAB)}}} there.

You can also arrange for state change notes (see [[Tracking TODO state
changes]]) and clock times (see [[*Clocking Work Time]]) to be stored in
a =LOGBOOK= drawer.  If you want to store a quick note there, in
a similar way to state changes, use

- {{{kbd(C-c C-z)}}} ::

  #+kindex: C-c C-z
  Add a time-stamped note to the =LOGBOOK= drawer.

** Blocks
:PROPERTIES:
:DESCRIPTION: Folding blocks.
:END:
#+vindex: org-hide-block-startup
#+cindex: blocks, folding

Org mode uses =#+BEGIN= ... =#+END= blocks for various purposes from
including source code examples (see [[*Literal Examples]]) to capturing
time logging information (see [[*Clocking Work Time]]).  These blocks can
be folded and unfolded by pressing {{{kbd(TAB)}}} in the =#+BEGIN=
line.  You can also get all blocks folded at startup by configuring
the variable ~org-hide-block-startup~ or on a per-file basis by using

#+cindex: STARTUP, keyword
#+begin_example
,#+STARTUP: hideblocks
,#+STARTUP: nohideblocks
#+end_example

* Tables
:PROPERTIES:
:DESCRIPTION: Pure magic for quick formatting.
:END:
#+cindex: tables
#+cindex: editing tables

Org comes with a fast and intuitive table editor.  Spreadsheet-like
calculations are supported using the Emacs Calc package (see [[info:calc][GNU Emacs
Calculator Manual]]).

** Built-in Table Editor
:PROPERTIES:
:DESCRIPTION: Simple tables.
:END:
#+cindex: table editor, built-in

#+cindex: header lines, in tables
#+cindex: horizontal rule, in tables
#+cindex: row separator, in tables
#+cindex: table syntax
Org makes it easy to format tables in plain ASCII.  Any line with =|=
as the first non-whitespace character is considered part of a table.
=|= is also the column separator[fn:: To insert a vertical bar into a
table field, use =\vert= or, inside a word =abc\vert{}def=.].
Moreover, a line starting with =|-= is a horizontal rule.  It
separates rows explicitly.  Rows before the first horizontal rule are
header lines.  A table might look like this:

#+begin_example
| Name  | Phone | Age |
|-------+-------+-----|
| Peter |  1234 |  17 |
| Anna  |  4321 |  25 |
#+end_example

A table is re-aligned automatically each time you press
{{{kbd(TAB)}}}, {{{kbd(RET)}}} or {{{kbd(C-c C-c)}}} inside the table.
{{{kbd(TAB)}}} also moves to the next field---{{{kbd(RET)}}} to the
next row---and creates new table rows at the end of the table or
before horizontal lines.  The indentation of the table is set by the
first line.  Horizontal rules are automatically expanded on every
re-align to span the whole table width.  So, to create the above
table, you would only type

#+begin_example
|Name|Phone|Age|
|-
#+end_example

#+texinfo: @noindent
and then press {{{kbd(TAB)}}} to align the table and start filling in
fields.  Even faster would be to type =|Name|Phone|Age= followed by
{{{kbd(C-c RET)}}}.

When typing text into a field, Org treats {{{kbd(DEL)}}},
{{{kbd(Backspace)}}}, and all character keys in a special way, so that
inserting and deleting avoids shifting other fields.  Also, when
typing /immediately/ after point was moved into a new field with
{{{kbd(TAB)}}}, {{{kbd(S-TAB)}}} or {{{kbd(RET)}}}, the field is
automatically made blank.  If this behavior is too unpredictable for
you, configure the option ~org-table-auto-blank-field~.

*** Creation and conversion
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- {{{kbd(C-c |)}}} (~org-table-create-or-convert-from-region~) ::

  #+kindex: C-c |
  #+findex: org-table-create-or-convert-from-region
  Convert the active region to table.  If every line contains at least
  one {{{kbd(TAB)}}} character, the function assumes that the material
  is tab separated.  If every line contains a comma, comma-separated
  values (CSV) are assumed.  If not, lines are split at whitespace
  into fields.  You can use a prefix argument to force a specific
  separator: {{{kbd(C-u)}}} forces CSV, {{{kbd(C-u C-u)}}} forces
  {{{kbd(TAB)}}}, {{{kbd(C-u C-u C-u)}}} prompts for a regular
  expression to match the separator, and a numeric argument
  N indicates that at least N consecutive spaces, or alternatively
  a {{{kbd(TAB)}}} will be the separator.

  If there is no active region, this command creates an empty Org
  table.  But it is easier just to start typing, like {{{kbd(|
  N a m e | P h o n e | A g e RET | - TAB)}}}.

*** Re-aligning and field motion
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- {{{kbd(C-c C-c)}}} (~org-table-align~) ::

  #+kindex: C-c C-c
  #+findex: org-table-align
  Re-align the table without moving point.

- {{{kbd(TAB)}}} (~org-table-next-field~) ::

  #+kindex: TAB
  #+findex: org-table-next-field
  Re-align the table, move to the next field.  Creates a new row if
  necessary.

- {{{kbd(M-x org-table-blank-field)}}} ::

  #+findex: org-table-blank-field
  Blank the current table field or active region.

- {{{kbd(S-TAB)}}} (~org-table-previous-field~) ::

  #+kindex: S-TAB
  #+findex: org-table-previous-field
  Re-align, move to previous field.

- {{{kbd(RET)}}} (~org-table-next-row~) ::

  #+kindex: RET
  #+findex: org-table-next-row
  Re-align the table and move down to next row.  Creates a new row if
  necessary.  At the beginning or end of a line, {{{kbd(RET)}}} still
  inserts a new line, so it can be used to split a table.

- {{{kbd(M-a)}}} (~org-table-beginning-of-field~) ::

  #+kindex: M-a
  #+findex: org-table-beginning-of-field
  Move to beginning of the current table field, or on to the previous
  field.

- {{{kbd(M-e)}}} (~org-table-end-of-field~) ::

  #+kindex: M-e
  #+findex: org-table-end-of-field
  Move to end of the current table field, or on to the next field.

*** Column and row editing
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- {{{kbd(M-LEFT)}}} (~org-table-move-column-left~) ::

  #+kindex: M-LEFT
  #+findex: org-table-move-column-left
  Move the current column left.

- {{{kbd(M-RIGHT)}}} (~org-table-move-column-right~) ::

  #+kindex: M-RIGHT
  #+findex: org-table-move-column-right
  Move the current column right.

- {{{kbd(M-S-LEFT)}}} (~org-table-delete-column~) ::

  #+kindex: M-S-LEFT
  #+findex: org-table-delete-column
  Kill the current column.

- {{{kbd(M-S-RIGHT)}}} (~org-table-insert-column~) ::

  #+kindex: M-S-RIGHT
  #+findex: org-table-insert-column
  Insert a new column at point position.  Move the recent column and
  all cells to the right of this column to the right.

- {{{kbd(M-UP)}}} (~org-table-move-row-up~) ::

  #+kindex: M-UP
  #+findex: org-table-move-row-up
  Move the current row up.

- {{{kbd(M-DOWN)}}} (~org-table-move-row-down~) ::

  #+kindex: M-DOWN
  #+findex: org-table-move-row-down
  Move the current row down.

- {{{kbd(M-S-UP)}}} (~org-table-kill-row~) ::

  #+kindex: M-S-UP
  #+findex: org-table-kill-row
  Kill the current row or horizontal line.

- {{{kbd(S-UP)}}} (~org-table-move-cell-up~) ::

  #+kindex: S-UP
  #+findex: org-table-move-cell-up
  Move cell up by swapping with adjacent cell.

- {{{kbd(S-DOWN)}}} (~org-table-move-cell-down~) ::

  #+kindex: S-DOWN
  #+findex: org-table-move-cell-down
  Move cell down by swapping with adjacent cell.

- {{{kbd(S-LEFT)}}} (~org-table-move-cell-left~) ::

  #+kindex: S-LEFT
  #+findex: org-table-move-cell-left
  Move cell left by swapping with adjacent cell.

- {{{kbd(S-RIGHT)}}} (~org-table-move-cell-right~) ::

  #+kindex: S-RIGHT
  #+findex: org-table-move-cell-right
  Move cell right by swapping with adjacent cell.

- {{{kbd(M-S-DOWN)}}} (~org-table-insert-row~) ::

  #+kindex: M-S-DOWN
  #+findex: org-table-insert-row
  Insert a new row above the current row.  With a prefix argument, the
  line is created below the current one.

- {{{kbd(C-c -)}}} (~org-table-insert-hline~) ::

  #+kindex: C-c -
  #+findex: org-table-insert-hline
  Insert a horizontal line below current row.  With a prefix argument,
  the line is created above the current line.

- {{{kbd(C-c RET)}}} (~org-table-hline-and-move~) ::

  #+kindex: C-c RET
  #+findex: org-table-hline-and-move
  Insert a horizontal line below current row, and move point into the
  row below that line.

- {{{kbd(C-c ^)}}} (~org-table-sort-lines~) ::

  #+kindex: C-c ^
  #+findex: org-table-sort-lines
  Sort the table lines in the region.  The position of point indicates
  the column to be used for sorting, and the range of lines is the
  range between the nearest horizontal separator lines, or the entire
  table.  If point is before the first column, you are prompted for
  the sorting column.  If there is an active region, the mark
  specifies the first line and the sorting column, while point should
  be in the last line to be included into the sorting.  The command
  prompts for the sorting type, alphabetically, numerically, or by
  time.  You can sort in normal or reverse order.  You can also supply
  your own key extraction and comparison functions.  When called with
  a prefix argument, alphabetic sorting is case-sensitive.

*** Regions
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- {{{kbd(C-c C-x M-w)}}} (~org-table-copy-region~) ::

  #+kindex: C-c C-x M-w
  #+findex: org-table-copy-region
  Copy a rectangular region from a table to a special clipboard.
  Point and mark determine edge fields of the rectangle.  If there is
  no active region, copy just the current field.  The process ignores
  horizontal separator lines.

- {{{kbd(C-c C-x C-w)}}} (~org-table-cut-region~) ::

  #+kindex: C-c C-x C-w
  #+findex: org-table-cut-region
  Copy a rectangular region from a table to a special clipboard, and
  blank all fields in the rectangle.  So this is the "cut" operation.

- {{{kbd(C-c C-x C-y)}}} (~org-table-paste-rectangle~) ::

  #+kindex: C-c C-x C-y
  #+findex: org-table-paste-rectangle
  Paste a rectangular region into a table.  The upper left corner ends
  up in the current field.  All involved fields are overwritten.  If
  the rectangle does not fit into the present table, the table is
  enlarged as needed.  The process ignores horizontal separator lines.

- {{{kbd(M-RET)}}} (~org-table-wrap-region~) ::

  #+kindex: M-RET
  #+findex: org-table-wrap-region
  Split the current field at point position and move the rest to the
  line below.  If there is an active region, and both point and mark
  are in the same column, the text in the column is wrapped to minimum
  width for the given number of lines.  A numeric prefix argument may
  be used to change the number of desired lines.  If there is no
  region, but you specify a prefix argument, the current field is made
  blank, and the content is appended to the field above.

*** Calculations
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: formula, in tables
#+cindex: calculations, in tables

- {{{kbd(C-c +)}}} (~org-table-sum~) ::

  #+kindex: C-c +
  #+findex: org-table-sum
  Sum the numbers in the current column, or in the rectangle defined
  by the active region.  The result is shown in the echo area and can
  be inserted with {{{kbd(C-y)}}}.

- {{{kbd(S-RET)}}} (~org-table-copy-down~) ::

  #+kindex: S-RET
  #+findex: org-table-copy-down
  #+vindex: org-table-copy-increment
  When current field is empty, copy from first non-empty field above.
  When not empty, copy current field down to next row and move point
  along with it.

  Depending on the variable ~org-table-copy-increment~, integer and
  time stamp field values, and fields prefixed or suffixed with
  a whole number, can be incremented during copy.  Also, a ~0~ prefix
  argument temporarily disables the increment.

  This key is also used by shift-selection and related modes (see
  [[*Packages that conflict with Org mode]]).

*** Miscellaneous
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- {{{kbd(C-c `)}}} (~org-table-edit-field~) ::

  #+kindex: C-c `
  #+findex: org-table-edit-field
  Edit the current field in a separate window.  This is useful for
  fields that are not fully visible (see [[*Column Width and Alignment]]).
  When called with a {{{kbd(C-u)}}} prefix, just make the full field
  visible, so that it can be edited in place.  When called with two
  {{{kbd(C-u)}}} prefixes, make the editor window follow point through
  the table and always show the current field.  The follow mode exits
  automatically when point leaves the table, or when you repeat this
  command with {{{kbd(C-u C-u C-c `)}}}.

- {{{kbd(M-x org-table-import)}}} ::

  #+findex: org-table-import
  Import a file as a table.  The table should be TAB or whitespace
  separated.  Use, for example, to import a spreadsheet table or data
  from a database, because these programs generally can write
  TAB-separated text files.  This command works by inserting the file
  into the buffer and then converting the region to a table.  Any
  prefix argument is passed on to the converter, which uses it to
  determine the separator.

- {{{kbd(C-c |)}}} (~org-table-create-or-convert-from-region~) ::

  #+kindex: C-c |
  #+findex: org-table-create-or-convert-from-region
  Tables can also be imported by pasting tabular text into the Org
  buffer, selecting the pasted text with {{{kbd(C-x C-x)}}} and then
  using the {{{kbd(C-c |)}}} command (see [[*Creation and conversion]]).

- {{{kbd(M-x org-table-export)}}} ::

  #+findex: org-table-export
  #+vindex: org-table-export-default-format
  Export the table, by default as a TAB-separated file.  Use for data
  exchange with, for example, spreadsheet or database programs.  The
  format used to export the file can be configured in the variable
  ~org-table-export-default-format~.  You may also use properties
  =TABLE_EXPORT_FILE= and =TABLE_EXPORT_FORMAT= to specify the file
  name and the format for table export in a subtree.  Org supports
  quite general formats for exported tables.  The exporter format is
  the same as the format used by Orgtbl radio tables, see [[*Translator
  functions]], for a detailed description.

- {{{kbd(M-x org-table-header-line-mode)}}} ::

  #+findex: org-table-header-line-mode
  #+vindex: org-table-header-line-p
  Turn on the display of the first data row of the table at point in
  the window header line when this first row is not visible anymore in
  the buffer.  You can activate this minor mode by default by setting
  the option ~org-table-header-line-p~ to ~t~.

- {{{kbd(M-x org-table-transpose-table-at-point)}}} ::

  #+findex: org-table-transpose-table-at-point
  Transpose the table at point and eliminate hlines.

** Column Width and Alignment
:PROPERTIES:
:DESCRIPTION: Overrule the automatic settings.
:END:
#+cindex: narrow columns in tables
#+cindex: alignment in tables

The width of columns is automatically determined by the table editor.
The alignment of a column is determined automatically from the
fraction of number-like versus non-number fields in the column.

#+vindex: org-table-automatic-realign
Editing a field may modify alignment of the table.  Moving
a contiguous row or column---i.e., using {{{kbd(TAB)}}} or
{{{kbd(RET)}}}---automatically re-aligns it.  If you want to disable
this behavior, set ~org-table-automatic-realign~ to ~nil~.  In any
case, you can always align manually a table:

- {{{kbd(C-c C-c)}}} (~org-table-align~) ::

  #+kindex: C-c C-c
  #+findex: org-table-align
  Align the current table.

#+vindex: org-startup-align-all-tables
Setting the option ~org-startup-align-all-tables~ re-aligns all tables
in a file upon visiting it.  You can also set this option on
a per-file basis with:

#+begin_example
,#+STARTUP: align
,#+STARTUP: noalign
#+end_example

Sometimes a single field or a few fields need to carry more text,
leading to inconveniently wide columns.  Maybe you want to hide away
several columns or display them with a fixed width, regardless of
content, as shown in the following example.

#+begin_example
|---+---------------------+--------|           |---+-------…+…|
|   | <6>                 |        |           |   | <6>   …|…|
| 1 | one                 | some   |   ----\   | 1 | one   …|…|
| 2 | two                 | boring |   ----/   | 2 | two   …|…|
| 3 | This is a long text | column |           | 3 | This i…|…|
|---+---------------------+--------|           |---+-------…+…|
#+end_example

To set the width of a column, one field anywhere in the column may
contain just the string =<N>= where {{{var(N)}}} specifies the width
as a number of characters.  You control displayed width of columns
with the following tools:

- {{{kbd(C-c TAB)}}} (~org-table-toggle-column-width~) ::

  #+kindex: C-c TAB
  #+findex: org-table-toggle-column-width
  Shrink or expand current column.

  If a width cookie specifies a width W for the column, shrinking it
  displays the first W visible characters only.  Otherwise, the column
  is shrunk to a single character.

  When called before the first column or after the last one, ask for
  a list of column ranges to operate on.

- {{{kbd(C-u C-c TAB)}}} (~org-table-shrink~) ::

  #+kindex: C-u C-c TAB
  #+findex: org-table-shrink
  Shrink all columns with a column width.  Expand the others.

- {{{kbd(C-u C-u C-c TAB)}}} (~org-table-expand~) ::

  #+kindex: C-u C-u C-c TAB
  #+findex: org-table-expand
  Expand all columns.

To see the full text of a shrunk field, hold the mouse over it:
a tool-tip window then shows the full contents of the field.
Alternatively, {{{kbd(C-h .)}}} (~display-local-help~) reveals them,
too.  For convenience, any change near the shrunk part of a column
expands it.

#+vindex: org-startup-shrink-all-tables
Setting the option ~org-startup-shrink-all-tables~ shrinks all columns
containing a width cookie in a file the moment it is visited.  You can
also set this option on a per-file basis with:

: #+STARTUP: shrink

If you would like to overrule the automatic alignment of number-rich
columns to the right and of string-rich columns to the left, you can
use =<r>=, =<c>= or =<l>= in a similar fashion.  You may also combine
alignment and field width like this: =<r10>=.

Lines which only contain these formatting cookies are removed
automatically upon exporting the document.

** Column Groups
:PROPERTIES:
:DESCRIPTION: Grouping to trigger vertical lines.
:END:
#+cindex: grouping columns in tables

When Org exports tables, it does so by default without vertical lines
because that is visually more satisfying in general.  Occasionally
however, vertical lines can be useful to structure a table into groups
of columns, much like horizontal lines can do for groups of rows.  In
order to specify column groups, you can use a special row where the
first field contains only =/=.  The further fields can either contain
=<= to indicate that this column should start a group, =>= to indicate
the end of a column, or =<>= (no space between =<= and =>=) to make
a column a group of its own.  Upon export, boundaries between column
groups are marked with vertical lines.  Here is an example:

#+begin_example
| N | N^2 | N^3 | N^4 | sqrt(n) | sqrt[4](N) |
|---+-----+-----+-----+---------+------------|
| / |  <  |     |  >  |       < |          > |
| 1 |  1  |  1  |  1  |       1 |          1 |
| 2 |  4  |  8  | 16  |  1.4142 |     1.1892 |
| 3 |  9  | 27  | 81  |  1.7321 |     1.3161 |
|---+-----+-----+-----+---------+------------|
,#+TBLFM: $2=$1^2::$3=$1^3::$4=$1^4::$5=sqrt($1)::$6=sqrt(sqrt(($1)))
#+end_example

It is also sufficient to just insert the column group starters after
every vertical line you would like to have:

#+begin_example
| N | N^2 | N^3 | N^4 | sqrt(n) | sqrt[4](N) |
|---+-----+-----+-----+---------+------------|
| / | <   |     |     | <       |            |
#+end_example

** The Orgtbl Minor Mode
:PROPERTIES:
:DESCRIPTION: The table editor as minor mode.
:ALT_TITLE: Orgtbl Mode
:END:
#+cindex: Orgtbl mode
#+cindex: minor mode for tables

#+findex: orgtbl-mode
If you like the intuitive way the Org table editor works, you might
also want to use it in other modes like Text mode or Mail mode.  The
minor mode Orgtbl mode makes this possible.  You can always toggle the
mode with {{{kbd(M-x orgtbl-mode)}}}.  To turn it on by default, for
example in Message mode, use

#+begin_src emacs-lisp
(add-hook 'message-mode-hook #'turn-on-orgtbl)
#+end_src

Furthermore, with some special setup, it is possible to maintain
tables in arbitrary syntax with Orgtbl mode.  For example, it is
possible to construct LaTeX tables with the underlying ease and power
of Orgtbl mode, including spreadsheet capabilities.  For details, see
[[*Tables in Arbitrary Syntax]].

** The Spreadsheet
:PROPERTIES:
:DESCRIPTION: The table editor has spreadsheet capabilities.
:END:
#+cindex: calculations, in tables
#+cindex: spreadsheet capabilities
#+cindex: Calc package

The table editor makes use of the Emacs Calc package to implement
spreadsheet-like capabilities.  It can also evaluate Emacs Lisp forms
to derive fields from other fields.  While fully featured, Org's
implementation is not identical to other spreadsheets.  For example,
Org knows the concept of a /column formula/ that will be applied to
all non-header fields in a column without having to copy the formula
to each relevant field.  There is also a formula debugger, and a
formula editor with features for highlighting fields in the table
corresponding to the references at point in the formula, moving these
references by arrow keys.

*** References
:PROPERTIES:
:DESCRIPTION: How to refer to another field or range.
:END:
#+cindex: references

To compute fields in the table from other fields, formulas must
reference other fields or ranges.  In Org, fields can be referenced by
name, by absolute coordinates, and by relative coordinates.  To find
out what the coordinates of a field are, press {{{kbd(C-c ?)}}} in
that field, or press {{{kbd(C-c })}}} to toggle the display of a grid.

**** Field references
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: field references
#+cindex: references, to fields
Formulas can reference the value of another field in two ways.  Like
in any other spreadsheet, you may reference fields with
a letter/number combination like =B3=, meaning the second field in the
third row.  However, Org prefers to use another, more general
representation that looks like this:[fn:7]

: @ROW$COLUMN

Column specifications can be absolute like =$1=, =$2=, ..., =$N=, or
relative to the current column, i.e., the column of the field which is
being computed, like =$+1= or =$-2=.  =$<= and =$>= are immutable
references to the first and last column, respectively, and you can use
=$>>>= to indicate the third column from the right.

The row specification only counts data lines and ignores horizontal
separator lines, or "hlines".  Like with columns, you can use absolute
row numbers =@1=, =@2=, ..., =@N=, and row numbers relative to the
current row like =@+3= or =@-1=.  =@<= and =@>= are immutable
references the first and last row in the table, respectively.  You may
also specify the row relative to one of the hlines: =@I= refers to the
first hline, =@II= to the second, etc.  =@-I= refers to the first such
line above the current line, =@+I= to the first such line below the
current line.  You can also write =@III+2= which is the second data
line after the third hline in the table.

=@0= and =$0= refer to the current row and column, respectively, i.e.,
to the row/column for the field being computed.  Also, if you omit
either the column or the row part of the reference, the current
row/column is implied.

Org's references with /unsigned/ numbers are fixed references in the
sense that if you use the same reference in the formula for two
different fields, the same field is referenced each time.  Org's
references with /signed/ numbers are floating references because the
same reference operator can reference different fields depending on
the field being calculated by the formula.

Here are a few examples:

#+attr_texinfo: :columns 0.2 0.8
| =@2$3=   | 2nd row, 3rd column (same as =C2=)                 |
| =$5=     | column 5 in the current row (same as =E&=)         |
| =@2=     | current column, row 2                              |
| =@-1$-3= | field one row up, three columns to the left        |
| =@-I$2=  | field just under hline above current row, column 2 |
| =@>$5=   | field in the last row, in column 5                 |

**** Range references
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: range references
#+cindex: references, to ranges
You may reference a rectangular range of fields by specifying two
field references connected by two dots =..=.  The ends are included in
the range.  If both fields are in the current row, you may simply use
=$2..$7=, but if at least one field is in a different row, you need to
use the general =@ROW$COLUMN= format at least for the first field,
i.e., the reference must start with =@= in order to be interpreted
correctly.  Examples:

#+attr_texinfo: :columns 0.2 0.8
| =$1..$3=      | first three fields in the current row                          |
| =$P..$Q=      | range, using column names (see [[*Advanced features]])             |
| =$<<<..$>>=   | start in third column, continue to the last but one            |
| =@2$1..@4$3=  | nine fields between these two fields (same as =A2..C4=)        |
| =@-1$-2..@-1= | 3 fields in the row above, starting from 2 columns on the left |
| =@I..II=      | between first and second hline, short for =@I..@II=            |

#+texinfo: @noindent
Range references return a vector of values that can be fed into Calc
vector functions.  Empty fields in ranges are normally suppressed, so
that the vector contains only the non-empty fields.  For other options
with the mode switches =E=, =N= and examples, see [[*Formula syntax for
Calc]].

**** Field coordinates in formulas
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: field coordinates
#+cindex: coordinates, of field
#+cindex: row, of field coordinates
#+cindex: column, of field coordinates
#+vindex: org-table-current-column
#+vindex: org-table-current-dline
One of the very first actions during evaluation of Calc formulas and
Lisp formulas is to substitute =@#= and =$#= in the formula with the
row or column number of the field where the current result will go to.
The traditional Lisp formula equivalents are ~org-table-current-dline~
and ~org-table-current-column~.  Examples:

- =if(@# % 2, $#, string(""))= ::

  Insert column number on odd rows, set field to empty on even rows.

- =$2 = '(identity remote(FOO, @@#$1))= ::

  Copy text or values of each row of column 1 of the table named
  {{{var(FOO)}}} into column 2 of the current table.

- =@3 = 2 * remote(FOO, @1$$#)= ::

  Insert the doubled value of each column of row 1 of the table
  named {{{var(FOO)}}} into row 3 of the current table.

#+texinfo: @noindent
For the second and third examples, table {{{var(FOO)}}} must have at
least as many rows or columns as the current table.  Note that this is
inefficient[fn:: The computation time scales as O(N^2) because table
{{{var(FOO)}}} is parsed for each field to be copied.] for large
number of rows.

**** Named references
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: named references
#+cindex: references, named
#+cindex: name, of column or field
#+cindex: constants, in calculations
#+cindex: @samp{CONSTANTS}, keyword
#+vindex: org-table-formula-constants

=$name= is interpreted as the name of a column, parameter or constant.
Constants are defined globally through the variable
~org-table-formula-constants~, and locally---for the file---through
a line like this example:

: #+CONSTANTS: c=299792458. pi=3.14 eps=2.4e-6

#+vindex: constants-unit-system
#+pindex: constants.el
Also, properties (see [[*Properties and Columns]]) can be used as
constants in table formulas: for a property =Xyz= use the name
=$PROP_Xyz=, and the property will be searched in the current outline
entry and in the hierarchy above it.  If you have the =constants.el=
package, it will also be used to resolve constants, including natural
constants like =$h= for Planck's constant, and units like =$km= for
kilometers[fn:8].  Column names and parameters can be specified in
special table lines.  These are described below, see [[*Advanced
features]].  All names must start with a letter, and further consist
of letters and numbers.

**** Remote references
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: remote references
#+cindex: references, remote
#+cindex: references, to a different table
#+cindex: name, of column or field
#+cindex: @samp{NAME}, keyword
You may also reference constants, fields and ranges from a different
table, either in the current file or even in a different file.  The
syntax is

: remote(NAME,REF)

#+texinfo: @noindent
where {{{var(NAME)}}} can be the name of a table in the current file
as set by a =#+NAME:= line before the table.  It can also be the ID of
an entry, even in a different file, and the reference then refers to
the first table in that entry.  {{{var(REF)}}} is an absolute field or
range reference as described above for example =@3$3= or =$somename=,
valid in the referenced table.

#+cindex: table indirection
When {{{var(NAME)}}} has the format =@ROW$COLUMN=, it is substituted
with the name or ID found in this field of the current table.  For
example =remote($1, @@>$2)= \Rightarrow =remote(year_2013, @@>$1)=.  The format
=B3= is not supported because it can not be distinguished from a plain
table name or ID.

*** Formula syntax for Calc
:PROPERTIES:
:DESCRIPTION: Using Calc to compute stuff.
:END:
#+cindex: formula syntax, Calc
#+cindex: syntax, of formulas

A formula can be any algebraic expression understood by the Emacs Calc
package.  Note that Calc has the non-standard convention that =/= has
lower precedence than =*=, so that =a/b*c= is interpreted as
=(a/(b*c))=.  Before evaluation by ~calc-eval~ (see [[info:calc#Calling Calc from Your Programs][Calling Calc from
Your Lisp Programs]]), variable substitution takes place according to
the rules described above.

#+cindex: vectors, in table calculations
The range vectors can be directly fed into the Calc vector functions
like ~vmean~ and ~vsum~.

#+cindex: format specifier, in spreadsheet
#+cindex: mode, for Calc
#+vindex: org-calc-default-modes
A formula can contain an optional mode string after a semicolon.  This
string consists of flags to influence Calc and other modes during
execution.  By default, Org uses the standard Calc modes (precision
12, angular units degrees, fraction and symbolic modes off).  The
display format, however, has been changed to =(float 8)= to keep
tables compact.  The default settings can be configured using the
variable ~org-calc-default-modes~.

- =p20= ::

  Set the internal Calc calculation precision to 20 digits.

- =n3=, =s3=, =e2=, =f4= ::

  Normal, scientific, engineering or fixed format of the result of
  Calc passed back to Org.  Calc formatting is unlimited in precision
  as long as the Calc calculation precision is greater.

- =D=, =R= ::

  Degree and radian angle modes of Calc.

- =F=, =S= ::

  Fraction and symbolic modes of Calc.

- =u= ::

  Units simplification mode of Calc.  Calc is also a symbolic
  calculator and is capable of working with values having a unit,
  represented with numerals followed by a unit string in Org table
  cells.  This mode instructs Calc to simplify the units in the
  computed expression before returning the result.

- =T=, =t=, =U= ::

  Duration computations in Calc or Lisp, [[*Durations and time values]].

- =E= ::

  If and how to consider empty fields.  Without =E= empty fields in
  range references are suppressed so that the Calc vector or Lisp list
  contains only the non-empty fields.  With =E= the empty fields are
  kept.  For empty fields in ranges or empty field references the
  value =nan= (not a number) is used in Calc formulas and the empty
  string is used for Lisp formulas.  Add =N= to use 0 instead for both
  formula types.  For the value of a field the mode =N= has higher
  precedence than =E=.

- =N= ::

  Interpret all fields as numbers, use 0 for non-numbers.  See the
  next section to see how this is essential for computations with Lisp
  formulas.  In Calc formulas it is used only occasionally because
  there number strings are already interpreted as numbers without =N=.

- =L= ::

  Literal, for Lisp formulas only.  See the next section.

Unless you use large integer numbers or high-precision calculation and
display for floating point numbers you may alternatively provide
a ~printf~ format specifier to reformat the Calc result after it has
been passed back to Org instead of letting Calc already do the
formatting[fn:9].  A few examples:

| =$1+$2=            | Sum of first and second field                    |
| =$1+$2;%.2f=       | Same, format result to two decimals              |
| =exp($2)+exp($1)=  | Math functions can be used                       |
| =$0;%.1f=          | Reformat current cell to 1 decimal               |
| =($3-32)*5/9=      | Degrees F \to C conversion                         |
| =$c/$1/$cm=        | Hz \to cm conversion, using =constants.el=         |
| =tan($1);Dp3s1=    | Compute in degrees, precision 3, display SCI 1   |
| =sin($1);Dp3%.1e=  | Same, but use ~printf~ specifier for display     |
| =vmean($2..$7)=    | Compute column range mean, using vector function |
| =vmean($2..$7);EN= | Same, but treat empty fields as 0                |
| =taylor($3,x=7,2)= | Taylor series of $3, at x=7, second degree       |

Calc also contains a complete set of logical operations (see [[info:calc#Logical Operations][Logical
Operations]]).  For example

- =if($1 < 20, teen, string(""))= ::

  ="teen"= if age =$1= is less than 20, else the Org table result
  field is set to empty with the empty string.

- =if("$1" =​= "nan" || "$2" =​= "nan", string(""), $1 + $2); E f-1= ::

  Sum of the first two columns.  When at least one of the input fields
  is empty the Org table result field is set to empty.  =E= is
  required to not convert empty fields to 0.  =f-1= is an optional
  Calc format string similar to =%.1f= but leaves empty results empty.

- =if(typeof(vmean($1..$7)) =​= 12, string(""), vmean($1..$7)); E= ::

  Mean value of a range unless there is any empty field.  Every field
  in the range that is empty is replaced by =nan= which lets =vmean=
  result in =nan=.  Then =typeof == 12= detects the =nan= from ~vmean~
  and the Org table result field is set to empty.  Use this when the
  sample set is expected to never have missing values.

- =if("$1..$7" =​= "[]", string(""), vmean($1..$7))= ::

  Mean value of a range with empty fields skipped.  Every field in the
  range that is empty is skipped.  When all fields in the range are
  empty the mean value is not defined and the Org table result field
  is set to empty.  Use this when the sample set can have a variable
  size.

- =vmean($1..$7); EN= ::

  To complete the example before: Mean value of a range with empty
  fields counting as samples with value 0.  Use this only when
  incomplete sample sets should be padded with 0 to the full size.

You can add your own Calc functions defined in Emacs Lisp with
~defmath~ and use them in formula syntax for Calc.

*** Emacs Lisp forms as formulas
:PROPERTIES:
:DESCRIPTION: Writing formulas in Emacs Lisp.
:ALT_TITLE: Formula syntax for Lisp
:END:
#+cindex: Lisp forms, as table formulas

It is also possible to write a formula in Emacs Lisp.  This can be
useful for string manipulation and control structures, if Calc's
functionality is not enough.

A formula is evaluated as a Lisp form when it starts with a
single-quote followed by an opening parenthesis.  Cell table
references are interpolated into the Lisp form before execution.  The
evaluation should return either a string or a number.  Evaluation
modes and a ~printf~ format used to render the returned values can be
specified after a semicolon.

By default, references are interpolated as literal Lisp strings: the
field content is replaced in the Lisp form stripped of leading and
trailing white space and surrounded in double-quotes.  For example:

: '(concat $1 $2)

#+texinfo: @noindent
concatenates the content of columns 1 and column 2.

When the =N= flag is used, all referenced elements are parsed as
numbers and interpolated as Lisp numbers, without quotes.  Fields that
cannot be parsed as numbers are interpolated as zeros.  For example:

: '(+ $1 $2);N

#+texinfo: @noindent
adds columns 1 and 2, equivalent to Calc's =$1+$2=.  Ranges are
inserted as space-separated fields, so they can be embedded in list or
vector syntax.  For example:

: '(apply '+ '($1..$4));N

#+texinfo: @noindent
computes the sum of columns 1 to 4, like Calc's =vsum($1..$4)=.

When the =L= flag is used, all fields are interpolated literally: the
cell content is replaced in the Lisp form stripped of leading and
trailing white space and without quotes.  If a reference is intended
to be interpreted as a string by the Lisp form, the reference operator
itself should be enclosed in double-quotes, like ="$3"=.  The =L= flag
is useful when strings and numbers are used in the same Lisp form.  For
example:

: '(substring "$1" $2 $3);L

#+texinfo: @noindent
extracts the part of the string in column 1 between the character
positions specified in the integers in column 2 and 3 and it is easier
to read than the equivalent:

: '(substring $1 (string-to-number $2) (string-to-number $3))

*** Durations and time values
:PROPERTIES:
:DESCRIPTION: How to compute durations and time values.
:END:
#+cindex: duration, computing
#+cindex: time, computing
#+vindex: org-table-duration-custom-format

If you want to compute time values use the =T=, =t=, or =U= flag,
either in Calc formulas or Elisp formulas:

#+begin_example
|  Task 1 |   Task 2 |    Total |
|---------+----------+----------|
|    2:12 |     1:47 | 03:59:00 |
|    2:12 |     1:47 |    03:59 |
| 3:02:20 | -2:07:00 |     0.92 |
,#+TBLFM: @2$3=$1+$2;T::@3$3=$1+$2;U::@4$3=$1+$2;t
#+end_example

Input duration values must be of the form =HH:MM[:SS]=, where seconds
are optional.  With the =T= flag, computed durations are displayed as
=HH:MM:SS= (see the first formula above).  With the =U= flag, seconds
are omitted so that the result is only =HH:MM= (see second formula
above).  Zero-padding of the hours field depends upon the value of the
variable ~org-table-duration-hour-zero-padding~.

With the =t= flag, computed durations are displayed according to the
value of the option ~org-table-duration-custom-format~, which defaults
to ~hours~ and displays the result as a fraction of hours (see the
third formula in the example above).

Negative duration values can be manipulated as well, and integers are
considered as seconds in addition and subtraction.

*** Field and range formulas
:PROPERTIES:
:DESCRIPTION: Formula for specific (ranges of) fields.
:END:
#+cindex: field formula
#+cindex: range formula
#+cindex: formula, for individual table field
#+cindex: formula, for range of fields

To assign a formula to a particular field, type it directly into the
field, preceded by =:==, for example =vsum(@II..III)=.  When you press
{{{kbd(TAB)}}} or {{{kbd(RET)}}} or {{{kbd(C-c C-c)}}} with point
still in the field, the formula is stored as the formula for this
field, evaluated, and the current field is replaced with the result.

#+cindex: @samp{TBLFM}, keyword
Formulas are stored in a special =TBLFM= keyword located directly
below the table.  If you type the equation in the fourth field of the
third data line in the table, the formula looks like =@3$4=$1+$2=.
When inserting/deleting/swapping column and rows with the appropriate
commands, /absolute references/ (but not relative ones) in stored
formulas are modified in order to still reference the same field.  To
avoid this from happening, in particular in range references, anchor
ranges at the table borders (using =@<=, =@>=, =$<=, =$>=), or at
hlines using the =@I= notation.  Automatic adaptation of field
references does not happen if you edit the table structure with normal
editing commands---you must fix the formulas yourself.

Instead of typing an equation into the field, you may also use the
following command

- {{{kbd(C-u C-c =)}}} (~org-table-eval-formula~) ::

  #+kindex: C-u C-c =
  #+findex: org-table-eval-formula
  Install a new formula for the current field.  The command prompts
  for a formula with default taken from the =TBLFM= keyword,
  applies it to the current field, and stores it.

The left-hand side of a formula can also be a special expression in
order to assign the formula to a number of different fields.  There is
no keyboard shortcut to enter such range formulas.  To add them, use
the formula editor (see [[*Editing and debugging formulas]]) or edit
the =TBLFM= keyword directly.

- =$2== ::

  Column formula, valid for the entire column.  This is so common that
  Org treats these formulas in a special way, see [[*Column formulas]].

- =@3== ::

  Row formula, applies to all fields in the specified row.  =@>==
  means the last row.

- =@1$2..@4$3== ::

  Range formula, applies to all fields in the given rectangular range.
  This can also be used to assign a formula to some but not all fields
  in a row.

- =$NAME== ::

  Named field, see [[*Advanced features]].

*** Column formulas
:PROPERTIES:
:DESCRIPTION: Formulas valid for an entire column.
:END:
#+cindex: column formula
#+cindex: formula, for table column

When you assign a formula to a simple column reference like =$3==, the
same formula is used in all fields of that column, with the following
very convenient exceptions: (i) If the table contains horizontal
separator hlines with rows above and below, everything before the
first such hline is considered part of the table /header/ and is not
modified by column formulas.  Therefore a header is mandatory when you
use column formulas and want to add hlines to group rows, like for
example to separate a total row at the bottom from the summand rows
above.  (ii) Fields that already get a value from a field/range
formula are left alone by column formulas.  These conditions make
column formulas very easy to use.

To assign a formula to a column, type it directly into any field in
the column, preceded by an equal sign, like ==$1+$2=.  When you press
{{{kbd(TAB)}}} or {{{kbd(RET)}}} or {{{kbd(C-c C-c)}}} with point
still in the field, the formula is stored as the formula for the
current column, evaluated and the current field replaced with the
result.  If the field contains only ===, the previously stored formula
for this column is used.  For each column, Org only remembers the most
recently used formula.  In the =TBLFM= keyword, column formulas look
like =$4=$1+$2=.  The left-hand side of a column formula can not be
the name of column, it must be the numeric column reference or =$>=.

Instead of typing an equation into the field, you may also use the
following command:

- {{{kbd(C-c =)}}} (~org-table-eval-formula~) ::

  #+kindex: C-c =
  #+findex: org-table-eval-formula
  Install a new formula for the current column and replace current
  field with the result of the formula.  The command prompts for
  a formula, with default taken from the =TBLFM= keyword, applies it
  to the current field and stores it.  With a numeric prefix argument,
  e.g., {{{kbd(C-5 C-c =)}}}, the command applies it to that many
  consecutive fields in the current column.

*** Lookup functions
:PROPERTIES:
:DESCRIPTION: Lookup functions for searching tables.
:END:
#+cindex: lookup functions in tables
#+cindex: table lookup functions

Org has three predefined Emacs Lisp functions for lookups in tables.

- =(org-lookup-first VAL S-LIST R-LIST &optional PREDICATE)= ::

  #+findex: org-lookup-first
  Searches for the first element {{{var(S)}}} in list
  {{{var(S-LIST)}}} for which
  #+begin_src emacs-lisp
  (PREDICATE VAL S)
  #+end_src
  is non-~nil~; returns the value from the corresponding position in
  list {{{var(R-LIST)}}}.  The default {{{var(PREDICATE)}}} is
  ~equal~.  Note that the parameters {{{var(VAL)}}} and {{{var(S)}}}
  are passed to {{{var(PREDICATE)}}} in the same order as the
  corresponding parameters are in the call to ~org-lookup-first~,
  where {{{var(VAL)}}} precedes {{{var(S-LIST)}}}.  If
  {{{var(R-LIST)}}} is ~nil~, the matching element {{{var(S)}}} of
  {{{var(S-LIST)}}} is returned.

- =(org-lookup-last VAL S-LIST R-LIST &optional PREDICATE)= ::

  #+findex: org-lookup-last
  Similar to ~org-lookup-first~ above, but searches for the /last/
  element for which {{{var(PREDICATE)}}} is non-~nil~.

- =(org-lookup-all VAL S-LIST R-LIST &optional PREDICATE)= ::

  #+findex: org-lookup-all
  Similar to ~org-lookup-first~, but searches for /all/ elements for
  which {{{var(PREDICATE)}}} is non-~nil~, and returns /all/
  corresponding values.  This function can not be used by itself in
  a formula, because it returns a list of values.  However, powerful
  lookups can be built when this function is combined with other Emacs
  Lisp functions.

If the ranges used in these functions contain empty fields, the =E=
mode for the formula should usually be specified: otherwise empty
fields are not included in {{{var(S-LIST)}}} and/or {{{var(R-LIST)}}}
which can, for example, result in an incorrect mapping from an element
of {{{var(S-LIST)}}} to the corresponding element of
{{{var(R-LIST)}}}.

These three functions can be used to implement associative arrays,
count matching cells, rank results, group data, etc.  For practical
examples see [[https://orgmode.org/worg/org-tutorials/org-lookups.html][this tutorial on Worg]].

*** Editing and debugging formulas
:PROPERTIES:
:DESCRIPTION: Fixing formulas.
:END:
#+cindex: formula editing
#+cindex: editing, of table formulas

#+vindex: org-table-use-standard-references
You can edit individual formulas in the minibuffer or directly in the
field.  Org can also prepare a special buffer with all active formulas
of a table.  When offering a formula for editing, Org converts
references to the standard format (like =B3= or =D&=) if possible.  If
you prefer to only work with the internal format (like =@3$2= or
=$4=), configure the variable ~org-table-use-standard-references~.

- {{{kbd(C-c =)}}} or {{{kbd(C-u C-c =)}}} (~org-table-eval-formula~) ::

  #+kindex: C-c =
  #+kindex: C-u C-c =
  #+findex: org-table-eval-formula
  Edit the formula associated with the current column/field in the
  minibuffer.  See [[*Column formulas]], and [[*Field and range formulas]].

- {{{kbd(C-u C-u C-c =)}}} (~org-table-eval-formula~) ::

  #+kindex: C-u C-u C-c =
  #+findex: org-table-eval-formula
  Re-insert the active formula (either a field formula, or a column
  formula) into the current field, so that you can edit it directly in
  the field.  The advantage over editing in the minibuffer is that you
  can use the command {{{kbd(C-c ?)}}}.

- {{{kbd(C-c ?)}}} (~org-table-field-info~) ::

  #+kindex: C-c ?
  #+findex: org-table-field-info
  While editing a formula in a table field, highlight the field(s)
  referenced by the reference at point position in the formula.

- {{{kbd(C-c })}}} (~org-table-toggle-coordinate-overlays~) ::

  #+kindex: C-c @}
  #+findex: org-table-toggle-coordinate-overlays
  Toggle the display of row and column numbers for a table, using
  overlays.  These are updated each time the table is aligned; you can
  force it with {{{kbd(C-c C-c)}}}.

- {{{kbd(C-c {)}}} (~org-table-toggle-formula-debugger~) ::

  #+kindex: C-c @{
  #+findex: org-table-toggle-formula-debugger
  Toggle the formula debugger on and off.  See below.

- {{{kbd(C-c ')}}} (~org-table-edit-formulas~) ::

  #+kindex: C-c '
  #+findex: org-table-edit-formulas
  Edit all formulas for the current table in a special buffer, where
  the formulas are displayed one per line.  If the current field has
  an active formula, point in the formula editor marks it.  While
  inside the special buffer, Org automatically highlights any field or
  range reference at point position.  You may edit, remove and add
  formulas, and use the following commands:

  - {{{kbd(C-c C-c)}}} or {{{kbd(C-x C-s)}}} (~org-table-fedit-finish~) ::

    #+kindex: C-x C-s
    #+kindex: C-c C-c
    #+findex: org-table-fedit-finish
    Exit the formula editor and store the modified formulas.  With
    {{{kbd(C-u)}}} prefix, also apply the new formulas to the
    entire table.

  - {{{kbd(C-c C-q)}}} (~org-table-fedit-abort~) ::

    #+kindex: C-c C-q
    #+findex: org-table-fedit-abort
    Exit the formula editor without installing changes.

  - {{{kbd(C-c C-r)}}} (~org-table-fedit-toggle-ref-type~) ::

    #+kindex: C-c C-r
    #+findex: org-table-fedit-toggle-ref-type
    Toggle all references in the formula editor between standard (like
    =B3=) and internal (like =@3$2=).

  - {{{kbd(TAB)}}} (~org-table-fedit-lisp-indent~) ::

    #+kindex: TAB
    #+findex: org-table-fedit-lisp-indent
    Pretty-print or indent Lisp formula at point.  When in a line
    containing a Lisp formula, format the formula according to Emacs
    Lisp rules.  Another {{{kbd(TAB)}}} collapses the formula back
    again.  In the open formula, {{{kbd(TAB)}}} re-indents just like
    in Emacs Lisp mode.

  - {{{kbd(M-TAB)}}} (~lisp-complete-symbol~) ::

    #+kindex: M-TAB
    #+findex: lisp-complete-symbol
    Complete Lisp symbols, just like in Emacs Lisp mode.

  - {{{kbd(S-UP)}}}, {{{kbd(S-DOWN)}}}, {{{kbd(S-LEFT)}}}, {{{kbd(S-RIGHT)}}} ::

    #+kindex: S-UP
    #+kindex: S-DOWN
    #+kindex: S-LEFT
    #+kindex: S-RIGHT
    #+findex: org-table-fedit-ref-up
    #+findex: org-table-fedit-ref-down
    #+findex: org-table-fedit-ref-left
    #+findex: org-table-fedit-ref-right
    Shift the reference at point.  For example, if the reference is
    =B3= and you press {{{kbd(S-RIGHT)}}}, it becomes =C3=.  This also
    works for relative references and for hline references.

  - {{{kbd(M-S-UP)}}} (~org-table-fedit-line-up~) ::

    #+kindex: M-S-UP
    #+findex: org-table-fedit-line-up
    Move the test line for column formulas up in the Org buffer.

  - {{{kbd(M-S-DOWN)}}} (~org-table-fedit-line-down~) ::

    #+kindex: M-S-DOWN
    #+findex: org-table-fedit-line-down
    Move the test line for column formulas down in the Org buffer.

  - {{{kbd(M-UP)}}} (~org-table-fedit-scroll-up~) ::

    #+kindex: M-UP
    #+findex: org-table-fedit-scroll-up
    Scroll up the window displaying the table.

  - {{{kbd(M-DOWN)}}} (~org-table-fedit-scroll-down~) ::

    #+kindex: M-DOWN
    #+findex: org-table-fedit-scroll-down
    Scroll down the window displaying the table.

  - {{{kbd(C-c })}}} ::

    #+kindex: C-c @}
    #+findex: org-table-toggle-coordinate-overlays
    Turn the coordinate grid in the table on and off.

Making a table field blank does not remove the formula associated with
the field, because that is stored in a different line---the =TBLFM=
keyword line.  During the next recalculation, the field will be filled
again.  To remove a formula from a field, you have to give an empty
reply when prompted for the formula, or to edit the =TBLFM= keyword.

#+kindex: C-c C-c
You may edit the =TBLFM= keyword directly and re-apply the changed
equations with {{{kbd(C-c C-c)}}} in that line or with the normal
recalculation commands in the table.

**** Using multiple =TBLFM= lines
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: multiple formula lines
#+cindex: @samp{TBLFM} keywords, multiple
#+cindex: @samp{TBLFM}, switching

#+kindex: C-c C-c
You may apply the formula temporarily.  This is useful when you want
to switch the formula applied to the table.  Place multiple =TBLFM=
keywords right after the table, and then press {{{kbd(C-c C-c)}}} on
the formula to apply.  Here is an example:

#+begin_example
| x | y |
|---+---|
| 1 |   |
| 2 |   |
,#+TBLFM: $2=$1*1
,#+TBLFM: $2=$1*2
#+end_example

#+texinfo: @noindent
Pressing {{{kbd(C-c C-c)}}} in the line of =#+TBLFM: $2=$1*2= yields:

#+begin_example
| x | y |
|---+---|
| 1 | 2 |
| 2 | 4 |
,#+TBLFM: $2=$1*1
,#+TBLFM: $2=$1*2
#+end_example

#+texinfo: @noindent
If you recalculate this table, with {{{kbd(C-u C-c *)}}}, for example,
you get the following result from applying only the first =TBLFM=
keyword.

#+begin_example
| x | y |
|---+---|
| 1 | 1 |
| 2 | 2 |
,#+TBLFM: $2=$1*1
,#+TBLFM: $2=$1*2
#+end_example

**** Debugging formulas
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: formula debugging
#+cindex: debugging, of table formulas

When the evaluation of a formula leads to an error, the field content
becomes the string =#ERROR=.  If you want to see what is going on
during variable substitution and calculation in order to find a bug,
turn on formula debugging in the Tbl menu and repeat the calculation,
for example by pressing {{{kbd(C-u C-u C-c = RET)}}} in a field.
Detailed information are displayed.

*** Updating the table
:PROPERTIES:
:DESCRIPTION: Recomputing all dependent fields.
:END:
#+cindex: recomputing table fields
#+cindex: updating, table

Recalculation of a table is normally not automatic, but needs to be
triggered by a command.  To make recalculation at least
semi-automatic, see [[*Advanced features]].

In order to recalculate a line of a table or the entire table, use the
following commands:

- {{{kbd(C-c *)}}} (~org-table-recalculate~) ::

  #+kindex: C-c *
  #+findex: org-table-recalculate
  Recalculate the current row by first applying the stored column
  formulas from left to right, and all field/range formulas in the
  current row.

- {{{kbd(C-u C-c *)}}} or {{{kbd(C-u C-c C-c)}}} ::

  #+kindex: C-u C-c *
  #+kindex: C-u C-c C-c
  Recompute the entire table, line by line.  Any lines before the
  first hline are left alone, assuming that these are part of the
  table header.

- {{{kbd(C-u C-u C-c *)}}} or {{{kbd(C-u C-u C-c C-c)}}} (~org-table-iterate~) ::

  #+kindex: C-u C-u C-c *
  #+kindex: C-u C-u C-c C-c
  #+findex: org-table-iterate
  Iterate the table by recomputing it until no further changes occur.
  This may be necessary if some computed fields use the value of other
  fields that are computed /later/ in the calculation sequence.

- {{{kbd(M-x org-table-recalculate-buffer-tables)}}} ::

  #+findex: org-table-recalculate-buffer-tables
  Recompute all tables in the current buffer.

- {{{kbd(M-x org-table-iterate-buffer-tables)}}} ::

  #+findex: org-table-iterate-buffer-tables
  Iterate all tables in the current buffer, in order to converge
  table-to-table dependencies.

*** Advanced features
:PROPERTIES:
:DESCRIPTION: Field and column names, automatic recalculation...
:END:

If you want the recalculation of fields to happen automatically, or if
you want to be able to assign /names/[fn:: Such names must start with
an alphabetic character and use only alphanumeric/underscore
characters.] to fields and columns, you need to reserve the first
column of the table for special marking characters.

- {{{kbd(C-#)}}} (~org-table-rotate-recalc-marks~) ::

  #+kindex: C-#
  #+findex: org-table-rotate-recalc-marks
  Rotate the calculation mark in first column through the states =#=,
  =*=, =!=, =$=.  When there is an active region, change all marks in
  the region.

Here is an example of a table that collects exam results of students
and makes use of these features:

#+begin_example
|---+---------+--------+--------+--------+-------+------|
|   | Student | Prob 1 | Prob 2 | Prob 3 | Total | Note |
|---+---------+--------+--------+--------+-------+------|
| ! |         |     P1 |     P2 |     P3 |   Tot |      |
| # | Maximum |     10 |     15 |     25 |    50 | 10.0 |
| ^ |         |     m1 |     m2 |     m3 |    mt |      |
|---+---------+--------+--------+--------+-------+------|
| # | Peter   |     10 |      8 |     23 |    41 |  8.2 |
| # | Sam     |      2 |      4 |      3 |     9 |  1.8 |
|---+---------+--------+--------+--------+-------+------|
|   | Average |        |        |        |  25.0 |      |
| ^ |         |        |        |        |    at |      |
| $ | max=50  |        |        |        |       |      |
|---+---------+--------+--------+--------+-------+------|
,#+TBLFM: $6=vsum($P1..$P3)::$7=10*$Tot/$max;%.1f::$at=vmean(@-II..@-I);%.1f
#+end_example

#+attr_texinfo: :tag Important
#+begin_quote
Please note that for these special tables, recalculating the table
with {{{kbd(C-u C-c *)}}} only affects rows that are marked =#= or
=*=, and fields that have a formula assigned to the field itself.  The
column formulas are not applied in rows with empty first field.
#+end_quote

#+cindex: marking characters, tables
The marking characters have the following meaning:

- =!= ::

  The fields in this line define names for the columns, so that you
  may refer to a column as =$Tot= instead of =$6=.

- =^= ::

  This row defines names for the fields /above/ the row.  With such
  a definition, any formula in the table may use =$m1= to refer to the
  value =10=.  Also, if you assign a formula to a names field, it is
  stored as =$name = ...=.

- =_= ::

  Similar to =^=, but defines names for the fields in the row /below/.

- =$= ::

  Fields in this row can define /parameters/ for formulas.  For
  example, if a field in a =$= row contains =max=50=, then formulas in
  this table can refer to the value 50 using =$max=.  Parameters work
  exactly like constants, only that they can be defined on a per-table
  basis.

- =#= ::

  Fields in this row are automatically recalculated when pressing
  {{{kbd(TAB)}}} or {{{kbd(RET)}}} or {{{kbd(S-TAB)}}} in this row.
  Also, this row is selected for a global recalculation with
  {{{kbd(C-u C-c *)}}}.  Unmarked lines are left alone by this
  command.

- =*= ::

  Selects this line for global recalculation with {{{kbd(C-u C-c
  *)}}}, but not for automatic recalculation.  Use this when automatic
  recalculation slows down editing too much.

- =/= ::

  Do not export this line.  Useful for lines that contain the
  narrowing =<N>= markers or column group markers.

Finally, just to whet your appetite for what can be done with the
fantastic Calc package, here is a table that computes the Taylor
series of degree n at location x for a couple of functions.

#+begin_example
|---+-------------+---+-----+--------------------------------------|
|   | Func        | n | x   | Result                               |
|---+-------------+---+-----+--------------------------------------|
| # | exp(x)      | 1 | x   | 1 + x                                |
| # | exp(x)      | 2 | x   | 1 + x + x^2 / 2                      |
| # | exp(x)      | 3 | x   | 1 + x + x^2 / 2 + x^3 / 6            |
| # | x^2+sqrt(x) | 2 | x=0 | x*(0.5 / 0) + x^2 (2 - 0.25 / 0) / 2 |
| # | x^2+sqrt(x) | 2 | x=1 | 2 + 2.5 x - 2.5 + 0.875 (x - 1)^2    |
| * | tan(x)      | 3 | x   | 0.0175 x + 1.77e-6 x^3               |
|---+-------------+---+-----+--------------------------------------|
,#+TBLFM: $5=taylor($2,$4,$3);n3
#+end_example

** Org Plot
:PROPERTIES:
:DESCRIPTION: Plotting from Org tables.
:END:
#+cindex: graph, in tables
#+cindex: plot tables using Gnuplot

Org Plot can produce graphs of information stored in Org tables,
either graphically or in ASCII art.

*** Graphical plots using Gnuplot
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: @samp{PLOT}, keyword
Org Plot can produce 2D and 3D graphs of information stored in Org
tables using [[https://www.gnuplot.info/][Gnuplot]] and [[http://cars9.uchicago.edu/~ravel/software/gnuplot-mode.html][Gnuplot mode]].  To see this in action, ensure
that you have both Gnuplot and Gnuplot mode installed on your system,
then call {{{kbd(C-c \quot g)}}} or {{{kbd(M-x org-plot/gnuplot)}}} on the
following table.

#+begin_example
,#+PLOT: title:"Citas" ind:1 deps:(3) type:2d with:histograms set:"yrange [0:]"
| Sede      | Max cites | H-index |
|-----------+-----------+---------|
| Chile     |    257.72 |   21.39 |
| Leeds     |    165.77 |   19.68 |
| Sao Paolo |     71.00 |   11.50 |
| Stockholm |    134.19 |   14.33 |
| Morelia   |    257.56 |   17.67 |
#+end_example

Org Plot supports a range of plot types, and provides the ability to add more.
For example, a radar plot can be generated like so:
#+begin_example
,#+PLOT: title:"An evaluation of plaintext document formats" transpose:yes type:radar min:0 max:4
| Format            | Fine-grained-control | Initial Effort | Syntax simplicity | Editor Support | Integrations | Ease-of-referencing | Versatility |
|-------------------+----------------------+----------------+-------------------+----------------+--------------+---------------------+-------------|
| Word              |                    2 |              4 |                 4 |              2 |            3 |                   2 |           2 |
| LaTeX             |                    4 |              1 |                 1 |              3 |            2 |                   4 |           3 |
| Org Mode          |                    4 |              2 |               3.5 |              1 |            4 |                   4 |           4 |
| Markdown          |                    1 |              3 |                 3 |              4 |            3 |                   3 |           1 |
| Markdown + Pandoc |                  2.5 |            2.5 |               2.5 |              3 |            3 |                   3 |           2 |
#+end_example

Notice that Org Plot is smart enough to apply the table's headers as
labels.  Further control over the labels, type, content, and
appearance of plots can be exercised through the =PLOT= keyword
preceding a table.  See below for a complete list of Org Plot options.
For more information and examples see the [[https://orgmode.org/worg/org-tutorials/org-plot.html][Org Plot tutorial]].

**** Plot options
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- =set= ::

  Specify any Gnuplot option to be set when graphing.

- =title= ::

  Specify the title of the plot.

- =ind= ::

  Specify which column of the table to use as the =x= axis.

- =deps= ::

  Specify the columns to graph as a Lisp style list, surrounded by
  parentheses and separated by spaces for example =dep:(3 4)= to graph
  the third and fourth columns.  Defaults to graphing all other
  columns aside from the =ind= column.

- transpose ::

  When =y=, =yes=, or =t= attempt to transpose the table data before
  plotting.  Also recognizes the shorthand option =trans=.

- =type= ::

  Specify the type of the plot, by default one of  =2d=, =3d=, =radar=, or =grid=.
  Available types can be customized with ~org-plot/preset-plot-types~.

- =with= ::

  Specify a =with= option to be inserted for every column being
  plotted, e.g., =lines=, =points=, =boxes=, =impulses=.  Defaults to
  =lines=.

- =file= ::

  If you want to plot to a file, specify
  ="path/to/desired/output-file"=.

- =labels= ::

  List of labels to be used for the =deps=.  Defaults to the column
  headers if they exist.

- =line= ::

  Specify an entire line to be inserted in the Gnuplot script.

- =map= ::

  When plotting =3d= or =grid= types, set this to =t= to graph a flat
  mapping rather than a =3d= slope.

- min ::

  Provides a minimum axis value that may be used by a plot type.
  Implicitly assumes the =y= axis is being referred to.  Can
  explicitly provide a value for a either the =x= or =y= axis with
  =xmin= and =ymin=.

- max ::

  Provides a maximum axis value that may be used by a plot type.
  Implicitly assumes the =y= axis is being referred to.  Can
  explicitly provide a value for a either the =x= or =y= axis with
  =xmax= and =ymax=.

- ticks ::

  Provides a desired number of axis ticks to display, that may be used
  by a plot type.  If none is given a plot type that requires ticks
  will use ~org--plot/sensible-tick-num~ to try to determine a good
  value.

- =timefmt= ::

  Specify format of Org mode timestamps as they will be parsed by
  Gnuplot.  Defaults to =%Y-%m-%d-%H:%M:%S=.

- =script= ::

  If you want total control, you can specify a script file---place the
  file name between double-quotes---which will be used to plot.
  Before plotting, every instance of =$datafile= in the specified
  script will be replaced with the path to the generated data file.
  Note: even if you set this option, you may still want to specify the
  plot type, as that can impact the content of the data file.

*** ASCII bar plots
:PROPERTIES:
:UNNUMBERED: notoc
:END:

While point is on a column, typing {{{kbd(C-c " a)}}} or {{{kbd(M-x
orgtbl-ascii-plot)}}} create a new column containing an ASCII-art bars
plot.  The plot is implemented through a regular column formula.  When
the source column changes, the bar plot may be updated by refreshing
the table, for example typing {{{kbd(C-u C-c *)}}}.

#+begin_example
| Sede          | Max cites |              |
|---------------+-----------+--------------|
| Chile         |    257.72 | WWWWWWWWWWWW |
| Leeds         |    165.77 | WWWWWWWh     |
| Sao Paolo     |     71.00 | WWW;         |
| Stockholm     |    134.19 | WWWWWW:      |
| Morelia       |    257.56 | WWWWWWWWWWWH |
| Rochefourchat |      0.00 |              |
,#+TBLFM: $3='(orgtbl-ascii-draw $2 0.0 257.72 12)
#+end_example

The formula is an Elisp call.

#+attr_texinfo: :options orgtbl-ascii-draw value min max &optional width
#+begin_defun
Draw an ASCII bar in a table.

{{{var(VALUE)}}} is the value to plot.

{{{var(MIN)}}} is the value displayed as an empty bar.  {{{var(MAX)}}}
is the value filling all the {{{var(WIDTH)}}}.  Sources values outside
this range are displayed as =too small= or =too large=.

{{{var(WIDTH)}}} is the number of characters of the bar plot.  It
defaults to =12=.
#+end_defun

* Hyperlinks
:PROPERTIES:
:DESCRIPTION: Notes in context.
:END:
#+cindex: hyperlinks

Like HTML, Org provides support for links inside a file, external
links to other files, Usenet articles, emails, and much more.

** Link Format
:PROPERTIES:
:DESCRIPTION: How links in Org are formatted.
:END:
#+cindex: link format
#+cindex: format, of links

#+cindex: angle bracket links
#+cindex: plain links
Org recognizes plain URIs, possibly wrapped within angle
brackets[fn:10], and activate them as clickable links.

#+cindex: bracket links
The general link format, however, looks like this:

: [[LINK][DESCRIPTION]]

#+texinfo: @noindent
or alternatively

: [[LINK]]

#+cindex: escape syntax, for links
#+cindex: backslashes, in links
Some =\=, =[= and =]= characters in the {{{var(LINK)}}} part need to
be "escaped", i.e., preceded by another =\= character.  More
specifically, the following characters, and only them, must be
escaped:

1. all =[= and =]= characters,
2. every =\= character preceding either =]= or =[=,
3. every =\= character at the end of the link.

#+findex: org-link-escape
Functions inserting links (see [[*Handling Links]]) properly escape
ambiguous characters.  You only need to bother about the rules above
when inserting directly, or yanking, a URI within square brackets.
When in doubt, you may use the function ~org-link-escape~, which turns
a link string into its escaped form.

Once a link in the buffer is complete, with all brackets present, Org
changes the display so that =DESCRIPTION= is displayed instead of
=[[LINK][DESCRIPTION]]= and =LINK= is displayed instead of =[[LINK]]=.
Links are highlighted in the ~org-link~ face, which, by default, is an
underlined face.

You can directly edit the visible part of a link.  This can be either
the {{{var(LINK)}}} part, if there is no description, or the
{{{var(DESCRIPTION)}}} part otherwise.  To also edit the invisible
{{{var(LINK)}}} part, use {{{kbd(C-c C-l)}}} with point on the link
(see [[*Handling Links]]).

If you place point at the beginning or just behind the end of the
displayed text and press {{{kbd(BS)}}}, you remove
the---invisible---bracket at that location[fn:: More accurately, the
precise behavior depends on how point arrived there---see
[[info:elisp#Invisible Text][Invisible Text]].].  This makes the link
incomplete and the internals are again displayed as plain text.
Inserting the missing bracket hides the link internals again.  To show
the internal structure of all links, use the menu: Org \rarr
Hyperlinks \rarr Literal links.

** Internal Links
:PROPERTIES:
:DESCRIPTION: Links to other places in the current file.
:END:
#+cindex: internal links
#+cindex: links, internal

A link that does not look like a URL---i.e., does not start with
a known scheme or a file name---refers to the current document.  You
can follow it with {{{kbd(C-c C-o)}}} when point is on the link, or
with a mouse click (see [[*Handling Links]]).

#+cindex: @samp{CUSTOM_ID}, property
Org provides several refinements to internal navigation within
a document.  Most notably, a construct like =[[#my-custom-id]]=
specifically targets the entry with the =CUSTOM_ID= property set to
=my-custom-id=.  Also, an internal link looking like =[[*Some
section]]= points to a headline with the name =Some section=[fn:11].

#+cindex: targets, for links
When the link does not belong to any of the cases above, Org looks for
a /dedicated target/: the same string in double angular brackets, like
=<<My Target>>=.

#+cindex: @samp{NAME}, keyword
If no dedicated target exists, the link tries to match the exact name
of an element within the buffer.  Naming is done, unsurprisingly, with
the =NAME= keyword, which has to be put in the line before the element
it refers to, as in the following example

#+begin_example
,#+NAME: My Target
| a  | table      |
|----+------------|
| of | four cells |
#+end_example

#+vindex: org-link-search-must-match-exact-headline
Ultimately, if none of the above succeeds, Org searches for a headline
that is exactly the link text but may also include a TODO keyword and
tags, or initiates a plain text search, according to the value of
~org-link-search-must-match-exact-headline~.

Note that you must make sure custom IDs, dedicated targets, and names
are unique throughout the document.  Org provides a linter to assist
you in the process, if needed.  See [[*Org Syntax]].

During export, internal links are used to mark objects and assign them
a number.  Marked objects are then referenced by links pointing to
them.  In particular, links without a description appear as the number
assigned to the marked object[fn:: When targeting a =NAME= keyword,
the =CAPTION= keyword is mandatory in order to get proper numbering
(see [[*Captions]]).].  In the following excerpt from an Org buffer

#+begin_example
1. one item
2. <<target>>another item
Here we refer to item [[target]].
#+end_example

#+texinfo: @noindent
The last sentence will appear as =Here we refer to item 2= when
exported.

In non-Org files, the search looks for the words in the link text.  In
the above example the search would be for =target=.

Following a link pushes a mark onto Org's own mark ring.  You can
return to the previous position with {{{kbd(C-c &)}}}.  Using this
command several times in direct succession goes back to positions
recorded earlier.

** Radio Targets
:PROPERTIES:
:DESCRIPTION: Make targets trigger links in plain text.
:END:
#+cindex: radio targets
#+cindex: targets, radio
#+cindex: links, radio targets

Org can automatically turn any occurrences of certain target names in
normal text into a link.  So without explicitly creating a link, the
text connects to the target radioing its position.  Radio targets are
enclosed by triple angular brackets.  For example, a target =<<<My
Target>>>= causes each occurrence of =my target= in normal text to
become activated as a link.  The Org file is scanned automatically for
radio targets only when the file is first loaded into Emacs.  To
update the target list during editing, press {{{kbd(C-c C-c)}}} with
point on or at a target.

** External Links
:PROPERTIES:
:DESCRIPTION: URL-like links to the world.
:END:
#+cindex: links, external
#+cindex: external links
#+cindex: attachment links
#+cindex: BBDB links
#+cindex: Elisp links
#+cindex: file links
#+cindex: Gnus links
#+cindex: Help links
#+cindex: IRC links
#+cindex: Info links
#+cindex: MH-E links
#+cindex: Rmail links
#+cindex: shell links
#+cindex: URL links
#+cindex: Usenet links

Org supports links to files, websites, Usenet and email messages, BBDB
database entries and links to both IRC conversations and their logs.
External links are URL-like locators.  They start with a short
identifying string followed by a colon.  There can be no space after
the colon.

Here is the full set of built-in link types:

- =file= ::

  File links.  File name may be remote, absolute, or relative.

  Additionally, you can specify a line number, or a text search.
  In Org files, you may link to a headline name, a custom ID, or a
  code reference instead.

  As a special case, "file" prefix may be omitted if the file name
  is complete, e.g., it starts with =./=, or =/=.

- =attachment= ::

  Same as file links but for files and folders attached to the current
  node (see [[*Attachments]]).  Attachment links are intended to behave
  exactly as file links but for files relative to the attachment
  directory.

- =bbdb= ::

  Link to a BBDB record, with possible regexp completion.

- =docview= ::

  Link to a document opened with DocView mode.  You may specify a page
  number.

- =doi= ::

  Link to an electronic resource, through its handle.

- =elisp= ::

  Execute an Elisp command upon activation.

- =gnus=, =rmail=, =mhe= ::

  Link to messages or folders from a given Emacs' MUA.

- =help= ::

  Display documentation of a symbol in =*Help*= buffer.

- =http=, =https= ::

  Web links.

- =id= ::

  Link to a specific headline by its ID property, in an Org file.

- =info= ::

  Link to an Info manual, or to a specific node.

- =irc= ::

  Link to an IRC channel.

- =mailto= ::

  Link to message composition.

- =news= ::

  Usenet links.

- =shell= ::

  Execute a shell command upon activation.

The following table illustrates the link types above, along with their
options:

| Link Type  | Example                                                  |
|------------+----------------------------------------------------------|
| http       | =http://staff.science.uva.nl/c.dominik/=                 |
| https      | =https://orgmode.org/=                                   |
| doi        | =doi:10.1000/182=                                        |
| file       | =file:/home/dominik/images/jupiter.jpg=                  |
|            | =/home/dominik/images/jupiter.jpg= (same as above)       |
|            | =file:papers/last.pdf=                                   |
|            | =./papers/last.pdf= (same as above)                      |
|            | =file:/ssh:me@some.where:papers/last.pdf= (remote)       |
|            | =/ssh:me@some.where:papers/last.pdf= (same as above)     |
|            | =file:sometextfile::NNN= (jump to line number)           |
|            | =file:projects.org=                                      |
|            | =file:projects.org::some words= (text search)[fn:12]     |
|            | =file:projects.org::*task title= (headline search)       |
|            | =file:projects.org::#custom-id= (headline search)        |
| attachment | =attachment:projects.org=                                |
|            | =attachment:projects.org::some words= (text search)      |
| docview    | =docview:papers/last.pdf::NNN=                           |
| id         | =id:B7423F4D-2E8A-471B-8810-C40F074717E9=                |
| news       | =news:comp.emacs=                                        |
| mailto     | =mailto:adent@galaxy.net=                                |
| mhe        | =mhe:folder= (folder link)                               |
|            | =mhe:folder#id= (message link)                           |
| rmail      | =rmail:folder= (folder link)                             |
|            | =rmail:folder#id= (message link)                         |
| gnus       | =gnus:group= (group link)                                |
|            | =gnus:group#id= (article link)                           |
| bbdb       | =bbdb:R.*Stallman= (record with regexp)                  |
| irc        | =irc:/irc.com/#emacs/bob=                                |
| help       | =help:org-store-link=                                    |
| info       | =info:org#External links=                                |
| shell      | =shell:ls *.org=                                         |
| elisp      | =elisp:(find-file "Elisp.org")= (Elisp form to evaluate) |
|            | =elisp:org-agenda= (interactive Elisp command)           |

#+cindex: VM links
#+cindex: Wanderlust links
On top of these built-in link types, additional ones are available
through the =org-contrib= repository (see [[*Installation]]).  For
example, these links to VM or Wanderlust messages are available when
you load the corresponding libraries from the =org-contrib=
repository:

| =vm:folder=                            | VM folder link          |
| =vm:folder#id=                         | VM message link         |
| =vm://myself@some.where.org/folder#id= | VM on remote machine    |
| =vm-imap:account:folder=               | VM IMAP folder link     |
| =vm-imap:account:folder#id=            | VM IMAP message link    |
| =wl:folder=                            | Wanderlust folder link  |
| =wl:folder#id=                         | Wanderlust message link |

For information on customizing Org to add new link types, see [[*Adding
Hyperlink Types]].

A link should be enclosed in double brackets and may contain
descriptive text to be displayed instead of the URL (see [[*Link
Format]]), for example:

: [[https://www.gnu.org/software/emacs/][GNU Emacs]]

If the description is a file name or URL that points to an image, HTML
export (see [[*HTML Export]]) inlines the image as a clickable button.  If
there is no description at all and the link points to an image, that
image is inlined into the exported HTML file.

#+cindex: square brackets, around links
#+cindex: angular brackets, around links
#+cindex: plain text external links
Org also recognizes external links amid normal text and activates them
as links.  If spaces must be part of the link (for example in
=bbdb:R.*Stallman=), or if you need to remove ambiguities about the
end of the link, enclose the link in square or angular brackets.

** Handling Links
:PROPERTIES:
:DESCRIPTION: Creating, inserting and following.
:END:
#+cindex: links, handling

Org provides methods to create a link in the correct syntax, to insert
it into an Org file, and to follow the link.

#+findex: org-store-link
#+cindex: storing links
The main function is ~org-store-link~, called with {{{kbd(M-x
org-store-link)}}}.  Because of its importance, we suggest to bind it
to a widely available key (see [[*Activation]]).  It stores a link to the
current location.  The link is stored for later insertion into an Org
buffer---see below.  The kind of link that is created depends on the
current buffer:

- /Org mode buffers/ ::

  For Org files, if there is a =<<target>>= at point, the link points
  to the target.  Otherwise it points to the current headline, which
  is also the description.

  #+vindex: org-id-link-to-org-use-id
  #+cindex: @samp{CUSTOM_ID}, property
  #+cindex: @samp{ID}, property
  If the headline has a =CUSTOM_ID= property, store a link to this
  custom ID.  In addition or alternatively, depending on the value of
  ~org-id-link-to-org-use-id~, create and/or use a globally unique
  =ID= property for the link[fn:: The Org Id library must first be
  loaded, either through ~org-customize~, by enabling ~id~ in
  ~org-modules~, or by adding =(require 'org-id)= in your Emacs init
  file.].  So using this command in Org buffers potentially creates
  two links: a human-readable link from the custom ID, and one that is
  globally unique and works even if the entry is moved from file to
  file.  The =ID= property can be either a UUID (default) or a
  timestamp, depending on ~org-id-method~.  Later, when inserting the
  link, you need to decide which one to use.

- /Email/News clients: VM, Rmail, Wanderlust, MH-E, Gnus/ ::

  #+vindex: org-link-email-description-format
  Pretty much all Emacs mail clients are supported.  The link points
  to the current article, or, in some Gnus buffers, to the group.  The
  description is constructed according to the variable
  ~org-link-email-description-format~.  By default, it refers to the
  addressee and the subject.

- /Web browsers: W3M and EWW/ ::

  Here the link is the current URL, with the page title as the
  description.

- /Contacts: BBDB/ ::

  Links created in a BBDB buffer point to the current entry.

- /Chat: IRC/ ::

  #+vindex: org-irc-links-to-logs
  For IRC links, if the variable ~org-irc-link-to-logs~ is non-~nil~,
  create a =file= style link to the relevant point in the logs for the
  current conversation.  Otherwise store an =irc= style link to the
  user/channel/server under the point.

- /Other files/ ::

  For any other file, the link points to the file, with a search
  string (see [[*Search Options in File Links]]) pointing to the contents
  of the current line.  If there is an active region, the selected
  words form the basis of the search string.  You can write custom Lisp
  functions to select the search string and perform the search for
  particular file types (see [[*Custom Searches]]).

  You can also define dedicated links to other files.  See [[*Adding
  Hyperlink Types]].

- /Agenda view/ ::

  When point is in an agenda view, the created link points to the
  entry referenced by the current line.

From an Org buffer, the following commands create, navigate or, more
generally, act on links.

#+attr_texinfo: :sep ,
- {{{kbd(C-c C-l)}}} (~org-insert-link~) ::

  #+kindex: C-c C-l
  #+findex: org-insert-link
  #+cindex: link completion
  #+cindex: completion, of links
  #+cindex: inserting links
  #+vindex: org-link-keep-stored-after-insertion
  Insert a link[fn:13].  This prompts for a link to be inserted into
  the buffer.  You can just type a link, using text for an internal
  link, or one of the link type prefixes mentioned in the examples
  above.  The link is inserted into the buffer, along with
  a descriptive text[fn:14].  If some text was selected at this time,
  it becomes the default description.

  - /Inserting stored links/ ::

    All links stored during the current session are part of the
    history for this prompt, so you can access them with {{{kbd(UP)}}}
    and {{{kbd(DOWN)}}} (or {{{kbd(M-p)}}}, {{{kbd(M-n)}}}).

  - /Completion support/ ::

    Completion with {{{kbd(TAB)}}} helps you to insert valid link
    prefixes like =http= or =ftp=, including the prefixes defined
    through link abbreviations (see [[*Link Abbreviations]]).  If you
    press {{{kbd(RET)}}} after inserting only the prefix, Org offers
    specific completion support for some link types[fn:: This works if
    a function has been defined in the ~:complete~ property of a link
    in ~org-link-parameters~.].  For example, if you type {{{kbd(f i l
    e RET)}}}---alternative access: {{{kbd(C-u C-c C-l)}}}, see
    below---Org offers file name completion, and after {{{kbd(b b d b
    RET)}}} you can complete contact names.

- {{{kbd(C-u C-c C-l)}}} ::

  #+cindex: file name completion
  #+cindex: completion, of file names
  #+kindex: C-u C-c C-l
  When {{{kbd(C-c C-l)}}} is called with a {{{kbd(C-u)}}} prefix
  argument, insert a link to a file.  You may use file name completion
  to select the name of the file.  The path to the file is inserted
  relative to the directory of the current Org file, if the linked
  file is in the current directory or in a sub-directory of it, or if
  the path is written relative to the current directory using =../=.
  Otherwise an absolute path is used, if possible with =~/= for your
  home directory.  You can force an absolute path with two
  {{{kbd(C-u)}}} prefixes.

- {{{kbd(C-c C-l)}}} (with point on existing link) ::

  #+cindex: following links
  When point is on an existing link, {{{kbd(C-c C-l)}}} allows you to
  edit the link and description parts of the link.

- {{{kbd(C-c C-o)}}} (~org-open-at-point~) ::

  #+kindex: C-c C-o
  #+findex: org-open-at-point
  #+vindex: org-file-apps
  Open link at point.  This launches a web browser for URL (using
  ~browse-url-at-point~), run VM/MH-E/Wanderlust/Rmail/Gnus/BBDB for
  the corresponding links, and execute the command in a shell link.
  When point is on an internal link, this command runs the
  corresponding search.  When point is on the tags part of a headline,
  it creates the corresponding tags view (see [[*Matching tags and
  properties]]).  If point is on a timestamp, it compiles the agenda for
  that date.  Furthermore, it visits text and remote files in =file=
  links with Emacs and select a suitable application for local
  non-text files.  Classification of files is based on file extension
  only.  See option ~org-file-apps~.  If you want to override the
  default application and visit the file with Emacs, use
  a {{{kbd(C-u)}}} prefix.  If you want to avoid opening in Emacs, use
  a {{{kbd(C-u C-u)}}} prefix.

  #+vindex: org-link-frame-setup
  If point is on a headline, but not on a link, offer all links in the
  headline and entry text.  If you want to setup the frame
  configuration for following links, customize ~org-link-frame-setup~.

- {{{kbd(RET)}}} ::

  #+vindex: org-return-follows-link
  #+kindex: RET
  When ~org-return-follows-link~ is set, {{{kbd(RET)}}} also follows
  the link at point.

- {{{kbd(mouse-2)}}} or {{{kbd(mouse-1)}}} ::

  #+kindex: mouse-2
  #+kindex: mouse-1
  On links, {{{kbd(mouse-1)}}} and {{{kbd(mouse-2)}}} opens the link
  just as {{{kbd(C-c C-o)}}} does.

- {{{kbd(mouse-3)}}} ::

  #+vindex: org-link-use-indirect-buffer-for-internals
  #+kindex: mouse-3
  Like {{{kbd(mouse-2)}}}, but force file links to be opened with
  Emacs, and internal links to be displayed in another window[fn:: See
  the variable ~org-link-use-indirect-buffer-for-internals~.].

- {{{kbd(C-c %)}}} (~org-mark-ring-push~) ::

  #+kindex: C-c %
  #+findex: org-mark-ring-push
  #+cindex: mark ring
  Push the current position onto the Org mark ring, to be able to
  return easily.  Commands following an internal link do this
  automatically.

- {{{kbd(C-c &)}}} (~org-mark-ring-goto~) ::

  #+kindex: C-c &
  #+findex: org-mark-ring-goto
  #+cindex: links, returning to
  Jump back to a recorded position.  A position is recorded by the
  commands following internal links, and by {{{kbd(C-c %)}}}.  Using
  this command several times in direct succession moves through a ring
  of previously recorded positions.

- {{{kbd(C-c C-x C-n)}}} (~org-next-link~), {{{kbd(C-c C-x C-p)}}} (~org-previous-link~) ::

  #+kindex: C-c C-x C-p
  #+findex: org-previous-link
  #+kindex: C-c C-x C-n
  #+findex: org-next-link
  #+cindex: links, finding next/previous
  Move forward/backward to the next link in the buffer.  At the limit
  of the buffer, the search fails once, and then wraps around.  The
  key bindings for this are really too long; you might want to bind
  this also to {{{kbd(M-n)}}} and {{{kbd(M-p)}}}.

  #+begin_src emacs-lisp
  (with-eval-after-load 'org
    (define-key org-mode-map (kbd "M-n") #'org-next-link)
    (define-key org-mode-map (kbd "M-p") #'org-previous-link))
  #+end_src

** Using Links Outside Org
:PROPERTIES:
:DESCRIPTION: Linking from my C source code?
:END:

#+findex: org-insert-link-global
#+findex: org-open-at-point-global
You can insert and follow links that have Org syntax not only in Org,
but in any Emacs buffer.  For this, Org provides two functions:
~org-insert-link-global~ and ~org-open-at-point-global~.

You might want to bind them to globally available keys.  See
[[*Activation]] for some advice.

** Link Abbreviations
:PROPERTIES:
:DESCRIPTION: Shortcuts for writing complex links.
:END:
#+cindex: link abbreviations
#+cindex: abbreviation, links

Long URL can be cumbersome to type, and often many similar links are
needed in a document.  For this you can use link abbreviations.  An
abbreviated link looks like this

: [[linkword:tag][description]]

#+texinfo: @noindent
#+vindex: org-link-abbrev-alist
where the tag is optional.  The /linkword/ must be a word, starting
with a letter, followed by letters, numbers, =-=, and =_=.
Abbreviations are resolved according to the information in the
variable ~org-link-abbrev-alist~ that relates the linkwords to
replacement text.  Here is an example:

#+begin_src emacs-lisp
(setq org-link-abbrev-alist
      '(("bugzilla"        . "http://10.1.2.9/bugzilla/show_bug.cgi?id=")
        ("Nu Html Checker" . "https://validator.w3.org/nu/?doc=%h")
        ("duckduckgo"      . "https://duckduckgo.com/?q=%s")
        ("omap"            . "https://nominatim.openstreetmap.org/search?q=%s&polygon=1")
        ("ads"             . "https://ui.adsabs.harvard.edu/search/q=%20author%3A\"%s\"")))
#+end_src

If the replacement text contains the string =%s=, it is replaced with
the tag.  Using =%h= instead of =%s= percent-encodes the tag (see the
example above, where we need to encode the URL parameter).  Using
=%(my-function)= passes the tag to a custom Lisp function, and replace
it by the resulting string.

If the replacement text do not contain any specifier, it is simply
appended to the string in order to create the link.

Instead of a string, you may also specify a Lisp function to create
the link.  Such a function will be called with the tag as the only
argument.

With the above setting, you could link to a specific bug with
=[[bugzilla:129]]=, search the web for =OrgMode= with =[[duckduckgo:OrgMode]]=,
show the map location of the Free Software Foundation =[[gmap:51
Franklin Street, Boston]]= or of Carsten office =[[omap:Science Park 904,
Amsterdam, The Netherlands]]= and find out what the Org author is doing
besides Emacs hacking with =[[ads:Dominik,C]]=.

If you need special abbreviations just for a single Org buffer, you
can define them in the file with

#+cindex: @samp{LINK}, keyword
#+begin_example
,#+LINK: bugzilla  https://10.1.2.9/bugzilla/show_bug.cgi?id=
,#+LINK: duckduckgo https://duckduckgo.com/?q=%s
,#+LINK: "Nu Html Checker" https://validator.w3.org/nu/?doc=%h
#+end_example

The abbreviations containing spaces must be quoted.

In-buffer completion (see [[*Completion]]) can be used after =[= to
complete link abbreviations.  You may also define a Lisp function that
implements special (e.g., completion) support for inserting such a
link with {{{kbd(C-c C-l)}}}.  Such a function should not accept any
arguments, and should return the full link with a prefix.  You can set
the link completion function like this:

#+begin_src emacs-lisp
(org-link-set-parameter "type" :complete #'some-completion-function)
#+end_src

** Search Options in File Links
:PROPERTIES:
:DESCRIPTION: Linking to a specific location.
:ALT_TITLE: Search Options
:END:
#+cindex: search option in file links
#+cindex: file links, searching
#+cindex: attachment links, searching

File links can contain additional information to make Emacs jump to a
particular location in the file when following a link.  This can be a
line number or a search option after a double colon[fn:: For backward
compatibility, line numbers can also follow a single colon.].  For
example, when the command ~org-store-link~ creates a link (see
[[*Handling Links]]) to a file, it encodes the words in the current
line as a search string that can be used to find this line back later
when following the link with {{{kbd(C-c C-o)}}}.

Note that all search options apply for Attachment links in the same
way that they apply for File links.

Here is the syntax of the different ways to attach a search to a file
link, together with explanations for each:

#+begin_example
[[file:~/code/main.c::255]]
[[file:~/xx.org::My Target]]
[[file:~/xx.org::*My Target]]
[[file:~/xx.org::#my-custom-id]]
[[file:~/xx.org::/regexp/]]
[[attachment:main.c::255]]
#+end_example

- =255= ::

  Jump to line 255.

- =My Target= ::

  Search for a link target =<<My Target>>=, or do a text search for
  =my target=, similar to the search in internal links, see [[*Internal
  Links]].  In HTML export (see [[*HTML Export]]), such a file link becomes
  a HTML reference to the corresponding named anchor in the linked
  file.

- =*My Target= ::

  In an Org file, restrict search to headlines.

- =#my-custom-id= ::

  Link to a heading with a =CUSTOM_ID= property

- =/REGEXP/= ::

  Do a regular expression search for {{{var(REGEXP)}}} (see [[*Regular
  Expressions]]).  This uses the Emacs command ~occur~ to list all
  matches in a separate window.  If the target file is in Org mode,
  ~org-occur~ is used to create a sparse tree with the matches.

As a degenerate case, a file link with an empty file name can be used
to search the current file.  For example, =[[file:::find me]]= does
a search for =find me= in the current file, just as =[[find me]]=
would.

** Custom Searches
:PROPERTIES:
:DESCRIPTION: When the default search is not enough.
:END:
#+cindex: custom search strings
#+cindex: search strings, custom

The default mechanism for creating search strings and for doing the
actual search related to a file link may not work correctly in all
cases.  For example, BibTeX database files have many entries like
~year="1993"~ which would not result in good search strings, because
the only unique identification for a BibTeX entry is the citation key.

#+vindex: org-create-file-search-functions
#+vindex: org-execute-file-search-functions
If you come across such a problem, you can write custom functions to
set the right search string for a particular file type, and to do the
search for the string in the file.  Using ~add-hook~, these functions
need to be added to the hook variables
~org-create-file-search-functions~ and
~org-execute-file-search-functions~.  See the docstring for these
variables for more information.  Org actually uses this mechanism for
BibTeX database files, and you can use the corresponding code as an
implementation example.  See the file =ol-bibtex.el=.

* TODO Items
:PROPERTIES:
:DESCRIPTION: Every tree branch can be a TODO item.
:END:
#+cindex: TODO items

Org mode does not maintain TODO lists as separate documents[fn:: Of
course, you can make a document that contains only long lists of TODO
items, but this is not required.].  Instead, TODO items are an
integral part of the notes file, because TODO items usually come up
while taking notes!  With Org mode, simply mark any entry in a tree as
being a TODO item.  In this way, information is not duplicated, and
the entire context from which the TODO item emerged is always present.

Of course, this technique for managing TODO items scatters them
throughout your notes file.  Org mode compensates for this by
providing methods to give you an overview of all the things that you
have to do.

** Basic TODO Functionality
:PROPERTIES:
:DESCRIPTION: Marking and displaying TODO entries.
:ALT_TITLE: TODO Basics
:END:

Any headline becomes a TODO item when it starts with the word =TODO=,
for example:

: *** TODO Write letter to Sam Fortune

The most important commands to work with TODO entries are:

- {{{kbd(C-c C-t)}}} (~org-todo~) ::

  #+kindex: C-c C-t
  #+cindex: cycling, of TODO states
  Rotate the TODO state of the current item among

  #+begin_example
  ,-> (unmarked) -> TODO -> DONE --.
  '--------------------------------'
  #+end_example

  If TODO keywords have fast access keys (see [[*Fast access to TODO
  states]]), prompt for a TODO keyword through the fast selection
  interface; this is the default behavior when
  ~org-use-fast-todo-selection~ is non-~nil~.

  The same state changing can also be done "remotely" from the agenda
  buffer with the {{{kbd(t)}}} command key (see [[*Commands in the
  Agenda Buffer]]).

- {{{kbd(S-RIGHT)}}} {{{kbd(S-LEFT)}}} ::

  #+kindex: S-RIGHT
  #+kindex: S-LEFT
  #+vindex: org-treat-S-cursor-todo-selection-as-state-change
  Select the following/preceding TODO state, similar to cycling.
  Useful mostly if more than two TODO states are possible (see
  [[*Extended Use of TODO Keywords]]).  See also [[*Packages that conflict
  with Org mode]], for a discussion of the interaction with
  shift-selection.  See also the variable
  ~org-treat-S-cursor-todo-selection-as-state-change~.

- {{{kbd(C-c / t)}}} (~org-show-todo-tree~) ::

  #+kindex: C-c / t
  #+cindex: sparse tree, for TODO
  #+vindex: org-todo-keywords
  #+findex: org-show-todo-tree
  View TODO items in a /sparse tree/ (see [[*Sparse Trees]]).  Folds the
  entire buffer, but shows all TODO items---with not-DONE state---and
  the headings hierarchy above them.  With a prefix argument, or by
  using {{{kbd(C-c / T)}}}, search for a specific TODO.  You are
  prompted for the keyword, and you can also give a list of keywords
  like =KWD1|KWD2|...= to list entries that match any one of these
  keywords.  With a numeric prefix argument N, show the tree for the
  Nth keyword in the variable ~org-todo-keywords~.  With two prefix
  arguments, find all TODO states, both un-done and done.

- {{{kbd(M-x org-agenda t)}}} (~org-todo-list~) ::

  #+kindex: t @r{(Agenda dispatcher)}
  Show the global TODO list.  Collects the TODO items (with not-DONE
  states) from all agenda files (see [[*Agenda Views]]) into a single
  buffer.  The new buffer is in Org Agenda mode, which provides
  commands to examine and manipulate the TODO entries from the new
  buffer (see [[*Commands in the Agenda Buffer]]).  See [[*The global TODO
  list]], for more information.

- {{{kbd(S-M-RET)}}} (~org-insert-todo-heading~) ::

  #+kindex: S-M-RET
  #+findex: org-insert-todo-heading
  Insert a new TODO entry below the current one.

#+vindex: org-todo-state-tags-triggers
Changing a TODO state can also trigger tag changes.  See the docstring
of the option ~org-todo-state-tags-triggers~ for details.

** Extended Use of TODO Keywords
:PROPERTIES:
:DESCRIPTION: Workflow and assignments.
:ALT_TITLE: TODO Extensions
:END:
#+cindex: extended TODO keywords

#+vindex: org-todo-keywords
By default, marked TODO entries have one of only two states: TODO and
DONE.  Org mode allows you to classify TODO items in more complex ways
with /TODO keywords/ (stored in ~org-todo-keywords~).  With special
setup, the TODO keyword system can work differently in different
files.

Note that /tags/ are another way to classify headlines in general and
TODO items in particular (see [[*Tags]]).

*** TODO keywords as workflow states
:PROPERTIES:
:DESCRIPTION: From TODO to DONE in steps.
:ALT_TITLE: Workflow states
:END:
#+cindex: TODO workflow
#+cindex: workflow states as TODO keywords

You can use TODO keywords to indicate different, possibly /sequential/
states in the process of working on an item, for example[fn:: Changing
the variable ~org-todo-keywords~ only becomes effective after
restarting Org mode in a buffer.]:

#+begin_src emacs-lisp
(setq org-todo-keywords
      '((sequence "TODO" "FEEDBACK" "VERIFY" "|" "DONE" "DELEGATED")))
#+end_src

The vertical bar separates the TODO keywords (states that /need
action/) from the DONE states (which need /no further action/).  If
you do not provide the separator bar, the last state is used as the
DONE state.

#+cindex: completion, of TODO keywords
With this setup, the command {{{kbd(C-c C-t)}}} cycles an entry from
=TODO= to =FEEDBACK=, then to =VERIFY=, and finally to =DONE= and
=DELEGATED=.  You may also use a numeric prefix argument to quickly
select a specific state.  For example {{{kbd(C-3 C-c C-t)}}} changes
the state immediately to =VERIFY=.  Or you can use {{{kbd(S-RIGHT)}}}
and {{{kbd(S-LEFT)}}} to go forward and backward through the states.
If you define many keywords, you can use in-buffer completion (see
[[*Completion]]) or a special one-key selection scheme (see [[*Fast
access to TODO states]]) to insert these words into the buffer.
Changing a TODO state can be logged with a timestamp, see [[*Tracking
TODO state changes]], for more information.

*** TODO keywords as types
:PROPERTIES:
:DESCRIPTION: I do this, Fred does the rest.
:ALT_TITLE: TODO types
:END:
#+cindex: TODO types
#+cindex: names as TODO keywords
#+cindex: types as TODO keywords

The second possibility is to use TODO keywords to indicate different
/types/ of action items.  For example, you might want to indicate that
items are for "work" or "home".  Or, when you work with several people
on a single project, you might want to assign action items directly to
persons, by using their names as TODO keywords.  This type of
functionality is actually much better served by using tags (see
[[*Tags]]), so the TODO implementation is kept just for backward
compatibility.

Using TODO types, it would be set up like this:

#+begin_src emacs-lisp
(setq org-todo-keywords '((type "Fred" "Sara" "Lucy" "|" "DONE")))
#+end_src

In this case, different keywords do not indicate states, but rather
different types.  So the normal work flow would be to assign a task to
a person, and later to mark it DONE.  Org mode supports this style by
adapting the workings of the command {{{kbd(C-c C-t)}}}[fn:: This is
also true for the {{{kbd(t)}}} command in the agenda buffer.].  When
used several times in succession, it still cycles through all names,
in order to first select the right type for a task.  But when you
return to the item after some time and execute {{{kbd(C-c C-t)}}}
again, it will switch from any name directly to =DONE=.  Use prefix
arguments or completion to quickly select a specific name.  You can
also review the items of a specific TODO type in a sparse tree by
using a numeric prefix to {{{kbd(C-c / t)}}}.  For example, to see all
things Lucy has to do, you would use {{{kbd(C-3 C-c / t)}}}.  To
collect Lucy's items from all agenda files into a single buffer, you
would use the numeric prefix argument as well when creating the global
TODO list: {{{kbd(C-3 M-x org-agenda t)}}}.

*** Multiple keyword sets in one file
:PROPERTIES:
:DESCRIPTION: Mixing it all, still finding your way.
:ALT_TITLE: Multiple sets in one file
:END:
#+cindex: TODO keyword sets

Sometimes you may want to use different sets of TODO keywords in
parallel.  For example, you may want to have the basic TODO/DONE, but
also a workflow for bug fixing, and a separate state indicating that
an item has been canceled---so it is not DONE, but also does not
require action.  Your setup would then look like this:

#+begin_src emacs-lisp
(setq org-todo-keywords
      '((sequence "TODO" "|" "DONE")
        (sequence "REPORT" "BUG" "KNOWNCAUSE" "|" "FIXED")
        (sequence "|" "CANCELED")))
#+end_src

The keywords should all be different, this helps Org mode keep track
of which subsequence should be used for a given entry.  In this setup,
{{{kbd(C-c C-t)}}} only operates within a sub-sequence, so it switches
from =DONE= to (nothing) to =TODO=, and from =FIXED= to (nothing) to
=REPORT=.  Therefore you need a mechanism to initially select the
correct sequence.  In addition to typing a keyword or using completion
(see [[*Completion]]), you may also apply the following commands:

#+attr_texinfo: :sep ,
- {{{kbd(C-u C-u C-c C-t)}}}, {{{kbd(C-S-RIGHT)}}}, {{{kbd(C-S-LEFT)}}} ::

  #+kindex: C-S-RIGHT
  #+kindex: C-S-LEFT
  #+kindex: C-u C-u C-c C-t
  These keys jump from one TODO sub-sequence to the next.  In the
  above example, {{{kbd(C-u C-u C-c C-t)}}} or {{{kbd(C-S-RIGHT)}}}
  would jump from =TODO= or =DONE= to =REPORT=, and any of the words
  in the second row to =CANCELED=.  Note that the {{{kbd(C-S-)}}} key
  binding conflict with shift-selection (see [[*Packages that conflict
  with Org mode]]).

- {{{kbd(S-RIGHT)}}}, {{{kbd(S-LEFT)}}} ::

  #+kindex: S-RIGHT
  #+kindex: S-LEFT
  {{{kbd(S-LEFT)}}} and {{{kbd(S-RIGHT)}}} walk through /all/ keywords
  from all sub-sequences, so for example {{{kbd(S-RIGHT)}}} would
  switch from =DONE= to =REPORT= in the example above.  For
  a discussion of the interaction with shift-selection, see [[*Packages
  that conflict with Org mode]].

*** Fast access to TODO states
:PROPERTIES:
:DESCRIPTION: Single letter selection of state.
:END:

If you would like to quickly change an entry to an arbitrary TODO
state instead of cycling through the states, you can set up keys for
single-letter access to the states.  This is done by adding the
selection character after each keyword, in parentheses[fn:: All
characters are allowed except =@=, =^= and =!=, which have a special
meaning here.].  For example:

#+begin_src emacs-lisp
(setq org-todo-keywords
      '((sequence "TODO(t)" "|" "DONE(d)")
        (sequence "REPORT(r)" "BUG(b)" "KNOWNCAUSE(k)" "|" "FIXED(f)")
        (sequence "|" "CANCELED(c)")))
#+end_src

#+vindex: org-fast-tag-selection-include-todo
If you then press {{{kbd(C-c C-t)}}} followed by the selection key,
the entry is switched to this state.  {{{kbd(SPC)}}} can be used to
remove any TODO keyword from an entry[fn:15].

*** Setting up keywords for individual files
:PROPERTIES:
:DESCRIPTION: Different files, different requirements.
:ALT_TITLE: Per-file keywords
:END:
#+cindex: keyword options
#+cindex: per-file keywords
#+cindex: @samp{TODO}, keyword
#+cindex: @samp{TYP_TODO}, keyword
#+cindex: @samp{SEQ_TODO}, keyword

It can be very useful to use different aspects of the TODO mechanism
in different files.  For file-local settings, you need to add special
lines to the file which set the keywords and interpretation for that
file only.  For example, to set one of the two examples discussed
above, you need one of the following lines, starting in column zero
anywhere in the file:

: #+TODO: TODO FEEDBACK VERIFY | DONE CANCELED

You may also write =#+SEQ_TODO= to be explicit about the
interpretation, but it means the same as =#+TODO=, or

: #+TYP_TODO: Fred Sara Lucy Mike | DONE

A setup for using several sets in parallel would be:

#+begin_example
,#+TODO: TODO(t) | DONE(d)
,#+TODO: REPORT(r) BUG(b) KNOWNCAUSE(k) | FIXED(f)
,#+TODO: | CANCELED(c)
#+end_example

#+cindex: completion, of option keywords
#+kindex: M-TAB
To make sure you are using the correct keyword, type =#+= into the
buffer and then use {{{kbd(M-TAB)}}} to complete it (see [[*Completion]]).

#+cindex: DONE, final TODO keyword
Remember that the keywords after the vertical bar---or the last
keyword if no bar is there---must always mean that the item is DONE,
although you may use a different word.  After changing one of these
lines, use {{{kbd(C-c C-c)}}} with point still in the line to make the
changes known to Org mode[fn:: Org mode parses these lines only when
Org mode is activated after visiting a file. {{{kbd(C-c C-c)}}} with
point in a line starting with =#+= is simply restarting Org mode for
the current buffer.].

*** Faces for TODO keywords
:PROPERTIES:
:DESCRIPTION: Highlighting states.
:END:
#+cindex: faces, for TODO keywords

#+vindex: org-todo, face
#+vindex: org-done, face
#+vindex: org-todo-keyword-faces
Org mode highlights TODO keywords with special faces: ~org-todo~ for
keywords indicating that an item still has to be acted upon, and
~org-done~ for keywords indicating that an item is finished.  If you
are using more than two different states, you might want to use
special faces for some of them.  This can be done using the variable
~org-todo-keyword-faces~.  For example:

#+begin_src emacs-lisp
(setq org-todo-keyword-faces
      '(("TODO" . org-warning) ("STARTED" . "yellow")
        ("CANCELED" . (:foreground "blue" :weight bold))))
#+end_src

#+vindex: org-faces-easy-properties
While using a list with face properties as shown for =CANCELED=
/should/ work, this does not always seem to be the case.  If
necessary, define a special face and use that.  A string is
interpreted as a color.  The variable ~org-faces-easy-properties~
determines if that color is interpreted as a foreground or
a background color.

*** TODO dependencies
:PROPERTIES:
:DESCRIPTION: When one task needs to wait for others.
:END:
#+cindex: TODO dependencies
#+cindex: dependencies, of TODO states

#+vindex: org-enforce-todo-dependencies
#+cindex: @samp{ORDERED}, property
The structure of Org files---hierarchy and lists---makes it easy to
define TODO dependencies.  Usually, a parent TODO task should not be
marked as done until all TODO subtasks, or children tasks, are marked
as done.  Sometimes there is a logical sequence to (sub)tasks, so that
one subtask cannot be acted upon before all siblings above it have
been marked as done.  If you customize the variable
~org-enforce-todo-dependencies~, Org blocks entries from changing
state to DONE while they have TODO children that are not DONE.
Furthermore, if an entry has a property =ORDERED=, each of its TODO
children is blocked until all earlier siblings are marked as done.
Here is an example:

#+begin_example
,* TODO Blocked until (two) is done
,** DONE one
,** TODO two

,* Parent
:PROPERTIES:
:ORDERED:  t
:END:
,** TODO a
,** TODO b, needs to wait for (a)
,** TODO c, needs to wait for (a) and (b)
#+end_example

#+cindex: TODO dependencies, @samp{NOBLOCKING}
#+cindex: @samp{NOBLOCKING}, property
You can ensure an entry is never blocked by using the =NOBLOCKING=
property (see [[*Properties and Columns]]):

#+begin_example
,* This entry is never blocked
:PROPERTIES:
:NOBLOCKING: t
:END:
#+end_example

- {{{kbd(C-c C-x o)}}} (~org-toggle-ordered-property~) ::

  #+kindex: C-c C-x o
  #+findex: org-toggle-ordered-property
  #+vindex: org-track-ordered-property-with-tag
  Toggle the =ORDERED= property of the current entry.  A property is
  used for this behavior because this should be local to the current
  entry, not inherited from entries above like a tag (see [[*Tags]]).
  However, if you would like to /track/ the value of this property
  with a tag for better visibility, customize the variable
  ~org-track-ordered-property-with-tag~.

- {{{kbd(C-u C-u C-u C-c C-t)}}} ::

  #+kindex: C-u C-u C-u C-u C-c C-t
  Change TODO state, regardless of any state blocking.

#+vindex: org-agenda-dim-blocked-tasks
If you set the variable ~org-agenda-dim-blocked-tasks~, TODO entries
that cannot be marked as done because of unmarked children are shown
in a dimmed font or even made invisible in agenda views (see [[*Agenda
Views]]).

#+cindex: checkboxes and TODO dependencies
#+vindex: org-enforce-todo-dependencies
You can also block changes of TODO states by using checkboxes (see
[[*Checkboxes]]).  If you set the variable
~org-enforce-todo-checkbox-dependencies~, an entry that has unchecked
checkboxes is blocked from switching to DONE.

If you need more complex dependency structures, for example
dependencies between entries in different trees or files, check out
the module =org-depend.el= in the =org-contrib= repository.

** Progress Logging
:PROPERTIES:
:DESCRIPTION: Dates and notes for progress.
:END:
#+cindex: progress logging
#+cindex: logging, of progress

To record a timestamp and a note when changing a TODO state, call the
command ~org-todo~ with a prefix argument.

- {{{kbd(C-u C-c C-t)}}} (~org-todo~) ::

  #+kindex: C-u C-c C-t
  Prompt for a note and record a the time of the TODO state change.
  The note is inserted as a list item below the headline, but can also
  be placed into a drawer, see [[*Tracking TODO state changes]].

If you want to be more systematic, Org mode can automatically record a
timestamp and optionally a note when you mark a TODO item as DONE, or
even each time you change the state of a TODO item.  This system is
highly configurable, settings can be on a per-keyword basis and can be
localized to a file or even a subtree.  For information on how to
clock working time for a task, see [[*Clocking Work Time]].

*** Closing items
:PROPERTIES:
:DESCRIPTION: When was this entry marked as done?
:END:

The most basic automatic logging is to keep track of /when/ a certain
TODO item was marked as done.  This can be achieved with[fn:: The
corresponding in-buffer setting is: =#+STARTUP: logdone=.]

#+begin_src emacs-lisp
(setq org-log-done 'time)
#+end_src

#+vindex: org-closed-keep-when-no-todo
#+texinfo: @noindent
Then each time you turn an entry from a TODO (not-done) state into any
of the DONE states, a line =CLOSED: [timestamp]= is inserted just
after the headline.  If you turn the entry back into a TODO item
through further state cycling, that line is removed again.  If you
turn the entry back to a non-TODO state (by pressing {{{kbd(C-c C-t
SPC)}}} for example), that line is also removed, unless you set
~org-closed-keep-when-no-todo~ to non-~nil~.  If you want to record a
note along with the timestamp, use[fn:: The corresponding in-buffer
setting is: =#+STARTUP: lognotedone=.]

#+begin_src emacs-lisp
(setq org-log-done 'note)
#+end_src

#+texinfo: @noindent
You are then prompted for a note, and that note is stored below the
entry with a =Closing Note= heading.

*** Tracking TODO state changes
:PROPERTIES:
:DESCRIPTION: When did the status change?
:END:
#+cindex: drawer, for state change recording

#+vindex: org-log-states-order-reversed
#+vindex: org-log-into-drawer
#+cindex: @samp{LOG_INTO_DRAWER}, property
You might want to automatically keep track of when a state change
occurred and maybe take a note about this change.  You can either
record just a timestamp, or a time-stamped note.  These records are
inserted after the headline as an itemized list, newest first[fn:: See
the variable ~org-log-states-order-reversed~.].  When taking a lot of
notes, you might want to get the notes out of the way into a drawer
(see [[*Drawers]]).  Customize the variable ~org-log-into-drawer~ to
get this behavior---the recommended drawer for this is called
=LOGBOOK=[fn:: Note that the =LOGBOOK= drawer is unfolded when
pressing {{{kbd(SPC)}}} in the agenda to show an entry---use
{{{kbd(C-u SPC)}}} to keep it folded here.].  You can also overrule
the setting of this variable for a subtree by setting a
=LOG_INTO_DRAWER= property.

Since it is normally too much to record a note for every state, Org
mode expects configuration on a per-keyword basis for this.  This is
achieved by adding special markers =!= (for a timestamp) or =@= (for
a note with timestamp) in parentheses after each keyword.  For
example, with the setting

#+begin_src emacs-lisp
(setq org-todo-keywords
      '((sequence "TODO(t)" "WAIT(w@/!)" "|" "DONE(d!)" "CANCELED(c@)")))
#+end_src

#+vindex: org-log-done
You not only define global TODO keywords and fast access keys, but
also request that a time is recorded when the entry is set to =DONE=,
and that a note is recorded when switching to =WAIT= or
=CANCELED=[fn:16].  The setting for =WAIT= is even more special: the
=!= after the slash means that in addition to the note taken when
entering the state, a timestamp should be recorded when /leaving/ the
=WAIT= state, if and only if the /target/ state does not configure
logging for entering it.  So it has no effect when switching from
=WAIT= to =DONE=, because =DONE= is configured to record a timestamp
only.  But when switching from =WAIT= back to =TODO=, the =/!= in the
=WAIT= setting now triggers a timestamp even though =TODO= has no
logging configured.

You can use the exact same syntax for setting logging preferences local
to a buffer:

: #+TODO: TODO(t) WAIT(w@/!) | DONE(d!) CANCELED(c@)

To record a timestamp without a note for TODO keywords configured with
=@=, just type {{{kbd(C-c C-c)}}} to enter a blank note when prompted.

#+cindex: @samp{LOGGING}, property
In order to define logging settings that are local to a subtree or
a single item, define a =LOGGING= property in this entry.  Any
non-empty =LOGGING= property resets all logging settings to ~nil~.
You may then turn on logging for this specific tree using =STARTUP=
keywords like =lognotedone= or =logrepeat=, as well as adding state
specific settings like =TODO(!)=.  For example:

#+begin_example
,* TODO Log each state with only a time
  :PROPERTIES:
  :LOGGING: TODO(!) WAIT(!) DONE(!) CANCELED(!)
  :END:
,* TODO Only log when switching to WAIT, and when repeating
  :PROPERTIES:
  :LOGGING: WAIT(@) logrepeat
  :END:
,* TODO No logging at all
  :PROPERTIES:
  :LOGGING: nil
  :END:
#+end_example

*** Tracking your habits
:PROPERTIES:
:DESCRIPTION: How consistent have you been?
:END:
#+cindex: habits
#+cindex: @samp{STYLE}, property

Org has the ability to track the consistency of a special category of
TODO, called "habits."  To use habits, you have to enable the ~habit~
module by customizing the variable ~org-modules~.

A habit has the following properties:

1. The habit is a TODO item, with a TODO keyword representing an open
   state.

2. The property =STYLE= is set to the value =habit= (see [[*Properties
   and Columns]]).

3. The TODO has a scheduled date, usually with a =.+= style repeat
   interval.  A =++= style may be appropriate for habits with time
   constraints, e.g., must be done on weekends, or a =+= style for an
   unusual habit that can have a backlog, e.g., weekly reports.

4. The TODO may also have minimum and maximum ranges specified by
   using the syntax =.+2d/3d=, which says that you want to do the task
   at least every three days, but at most every two days.

5. State logging for the DONE state is enabled (see [[*Tracking TODO
   state changes]]), in order for historical data to be represented in
   the consistency graph.  If it is not enabled it is not an error,
   but the consistency graphs are largely meaningless.

To give you an idea of what the above rules look like in action, here's an
actual habit with some history:

#+begin_example
,** TODO Shave
   SCHEDULED: <2009-10-17 Sat .+2d/4d>
   :PROPERTIES:
   :STYLE:    habit
   :LAST_REPEAT: [2009-10-19 Mon 00:36]
   :END:
   - State "DONE"       from "TODO"       [2009-10-15 Thu]
   - State "DONE"       from "TODO"       [2009-10-12 Mon]
   - State "DONE"       from "TODO"       [2009-10-10 Sat]
   - State "DONE"       from "TODO"       [2009-10-04 Sun]
   - State "DONE"       from "TODO"       [2009-10-02 Fri]
   - State "DONE"       from "TODO"       [2009-09-29 Tue]
   - State "DONE"       from "TODO"       [2009-09-25 Fri]
   - State "DONE"       from "TODO"       [2009-09-19 Sat]
   - State "DONE"       from "TODO"       [2009-09-16 Wed]
   - State "DONE"       from "TODO"       [2009-09-12 Sat]
#+end_example

What this habit says is: I want to shave at most every 2 days---given
by the =SCHEDULED= date and repeat interval---and at least every
4 days.  If today is the 15th, then the habit first appears in the
agenda (see [[*Agenda Views]]) on Oct 17, after the minimum of 2 days has
elapsed, and will appear overdue on Oct 19, after four days have
elapsed.

What's really useful about habits is that they are displayed along
with a consistency graph, to show how consistent you've been at
getting that task done in the past.  This graph shows every day that
the task was done over the past three weeks, with colors for each day.
The colors used are:

- Blue :: If the task was not to be done yet on that day.
- Green :: If the task could have been done on that day.
- Yellow :: If the task was going to be overdue the next day.
- Red :: If the task was overdue on that day.

In addition to coloring each day, the day is also marked with an
asterisk if the task was actually done that day, and an exclamation
mark to show where the current day falls in the graph.

There are several configuration variables that can be used to change
the way habits are displayed in the agenda.

- ~org-habit-graph-column~ ::

  #+vindex: org-habit-graph-column
  The buffer column at which the consistency graph should be drawn.
  This overwrites any text in that column, so it is a good idea to
  keep your habits' titles brief and to the point.

- ~org-habit-preceding-days~ ::

  #+vindex: org-habit-preceding-days
  The amount of history, in days before today, to appear in
  consistency graphs.

- ~org-habit-following-days~ ::

  #+vindex: org-habit-following-days
  The number of days after today that appear in consistency graphs.

- ~org-habit-show-habits-only-for-today~ ::

  #+vindex: org-habit-show-habits-only-for-today
  If non-~nil~, only show habits in today's agenda view.  The default
  value is ~t~.  Pressing {{{kbd(C-u K)}}} in the agenda toggles this
  variable.

Lastly, pressing {{{kbd(K)}}} in the agenda buffer causes habits to
temporarily be disabled and do not appear at all.  Press {{{kbd(K)}}}
again to bring them back.  They are also subject to tag filtering, if
you have habits which should only be done in certain contexts, for
example.

** Priorities
:PROPERTIES:
:DESCRIPTION: Some things are more important than others.
:END:
#+cindex: priorities
#+cindex: priority cookie

If you use Org mode extensively, you may end up with enough TODO items
that it starts to make sense to prioritize them.  Prioritizing can be
done by placing a /priority cookie/ into the headline of a TODO item
right after the TODO keyword, like this:

: *** TODO [#A] Write letter to Sam Fortune

#+vindex: org-priority-faces
By default, Org mode supports three priorities: =A=, =B=, and =C=.
=A= is the highest priority.  An entry without a cookie is treated as
equivalent if it had priority =B=.  Priorities make a difference only
for sorting in the agenda (see [[*Weekly/daily agenda]]).  Outside the
agenda, they have no inherent meaning to Org mode.  The cookies are
displayed with the face defined by the variable ~org-priority-faces~,
which can be customized.

You can also use numeric values for priorities, such as

: *** TODO [#1] Write letter to Sam Fortune

When using numeric priorities, you need to set ~org-priority-highest~,
~org-priority-lowest~ and ~org-priority-default~ to integers, which
must all be strictly inferior to 65.

Priorities can be attached to any outline node; they do not need to be
TODO items.

#+attr_texinfo: :sep ;
- {{{kbd(C-c \,)}}} (~org-priority~) ::

  #+kindex: C-c ,
  #+findex: org-priority
  Set the priority of the current headline.  The command prompts for
  a priority character =A=, =B= or =C=.  When you press {{{kbd(SPC)}}}
  instead, the priority cookie, if one is set, is removed from the
  headline.  The priorities can also be changed "remotely" from the
  agenda buffer with the {{{kbd(\,)}}} command (see [[*Commands in the
  Agenda Buffer]]).

- {{{kbd(S-UP)}}} (~org-priority-up~); {{{kbd(S-DOWN)}}} (~org-priority-down~) ::

  #+kindex: S-UP
  #+kindex: S-DOWN
  #+findex: org-priority-up
  #+findex: org-priority-down
  #+vindex: org-priority-start-cycle-with-default
  Increase/decrease the priority of the current headline[fn:: See also
  the option ~org-priority-start-cycle-with-default~.].  Note that
  these keys are also used to modify timestamps (see [[*Creating
  Timestamps]]).  See also [[*Packages that conflict with Org mode]],
  for a discussion of the interaction with shift-selection.

#+vindex: org-priority-highest
#+vindex: org-priority-lowest
#+vindex: org-priority-default
You can change the range of allowed priorities by setting the
variables ~org-priority-highest~, ~org-priority-lowest~, and
~org-priority-default~.  For an individual buffer, you may set these
values (highest, lowest, default) like this (please make sure that the
highest priority is earlier in the alphabet than the lowest priority):

#+cindex: @samp{PRIORITIES}, keyword
: #+PRIORITIES: A C B

Or, using numeric values:

: #+PRIORITIES: 1 10 5

** Breaking Down Tasks into Subtasks
:PROPERTIES:
:DESCRIPTION: Splitting a task into manageable pieces.
:ALT_TITLE: Breaking Down Tasks
:END:
#+cindex: tasks, breaking down
#+cindex: statistics, for TODO items

#+vindex: org-agenda-todo-list-sublevels
It is often advisable to break down large tasks into smaller,
manageable subtasks.  You can do this by creating an outline tree
below a TODO item, with detailed subtasks on the tree[fn:: To keep
subtasks out of the global TODO list, see the option
~org-agenda-todo-list-sublevels~.].  To keep an overview of the
fraction of subtasks that have already been marked as done, insert
either =[/]= or =[%]= anywhere in the headline.  These cookies are
updated each time the TODO status of a child changes, or when pressing
{{{kbd(C-c C-c)}}} on the cookie.  For example:

#+begin_example
,* Organize Party [33%]
,** TODO Call people [1/2]
,*** TODO Peter
,*** DONE Sarah
,** TODO Buy food
,** DONE Talk to neighbor
#+end_example

#+cindex: @samp{COOKIE_DATA}, property
If a heading has both checkboxes and TODO children below it, the
meaning of the statistics cookie become ambiguous.  Set the property
=COOKIE_DATA= to either =checkbox= or =todo= to resolve this issue.

#+vindex: org-hierarchical-todo-statistics
If you would like to have the statistics cookie count any TODO entries
in the subtree (not just direct children), configure the variable
~org-hierarchical-todo-statistics~.  To do this for a single subtree,
include the word =recursive= into the value of the =COOKIE_DATA=
property.

#+begin_example
,* Parent capturing statistics [2/20]
  :PROPERTIES:
  :COOKIE_DATA: todo recursive
  :END:
#+end_example

If you would like a TODO entry to automatically change to DONE when
all children are done, you can use the following setup:

#+begin_src emacs-lisp
(defun org-summary-todo (n-done n-not-done)
  "Switch entry to DONE when all subentries are done, to TODO otherwise."
  (let (org-log-done org-log-states)   ; turn off logging
    (org-todo (if (= n-not-done 0) "DONE" "TODO"))))

(add-hook 'org-after-todo-statistics-hook #'org-summary-todo)
#+end_src

Another possibility is the use of checkboxes to identify (a hierarchy
of) a large number of subtasks (see [[*Checkboxes]]).

** Checkboxes
:PROPERTIES:
:DESCRIPTION: Tick-off lists.
:END:
#+cindex: checkboxes

#+vindex: org-list-automatic-rules
Every item in a plain list[fn:17] (see [[*Plain Lists]]) can be made into
a checkbox by starting it with the string =[ ]=.  This feature is
similar to TODO items (see [[*TODO Items]]), but is more lightweight.
Checkboxes are not included into the global TODO list, so they are
often great to split a task into a number of simple steps.  Or you can
use them in a shopping list.

Here is an example of a checkbox list.

#+begin_example
,* TODO Organize party [2/4]
  - [-] call people [1/3]
    - [ ] Peter
    - [X] Sarah
    - [ ] Sam
  - [X] order food
  - [ ] think about what music to play
  - [X] talk to the neighbors
#+end_example

Checkboxes work hierarchically, so if a checkbox item has children
that are checkboxes, toggling one of the children checkboxes makes the
parent checkbox reflect if none, some, or all of the children are
checked.

#+cindex: statistics, for checkboxes
#+cindex: checkbox statistics
#+cindex: @samp{COOKIE_DATA}, property
#+vindex: org-hierarchical-checkbox-statistics
The =[2/4]= and =[1/3]= in the first and second line are cookies
indicating how many checkboxes present in this entry have been checked
off, and the total number of checkboxes present.  This can give you an
idea on how many checkboxes remain, even without opening a folded
entry.  The cookies can be placed into a headline or into (the first
line of) a plain list item.  Each cookie covers checkboxes of direct
children structurally below the headline/item on which the cookie
appears[fn:: Set the variable ~org-hierarchical-checkbox-statistics~
if you want such cookies to count all checkboxes below the cookie, not
just those belonging to direct children.].  You have to insert the
cookie yourself by typing either =[/]= or =[%]=.  With =[/]= you get
an =n out of m= result, as in the examples above.  With =[%]= you get
information about the percentage of checkboxes checked (in the above
example, this would be =[50%]= and =[33%]=, respectively).  In a
headline, a cookie can count either checkboxes below the heading or
TODO states of children, and it displays whatever was changed last.
Set the property =COOKIE_DATA= to either =checkbox= or =todo= to
resolve this issue.

#+cindex: blocking, of checkboxes
#+cindex: checkbox blocking
#+cindex: @samp{ORDERED}, property
If the current outline node has an =ORDERED= property, checkboxes must
be checked off in sequence, and an error is thrown if you try to check
off a box while there are unchecked boxes above it.

The following commands work with checkboxes:

- {{{kbd(C-c C-c)}}} (~org-toggle-checkbox~) ::

  #+kindex: C-c C-c
  #+findex: org-toggle-checkbox
  Toggle checkbox status or---with prefix argument---checkbox presence
  at point.  With a single prefix argument, add an empty checkbox or
  remove the current one[fn:: {{{kbd(C-u C-c C-c)}}} on the /first/
  item of a list with no checkbox adds checkboxes to the rest of the
  list.].  With a double prefix argument, set it to =[-]=, which is
  considered to be an intermediate state.

- {{{kbd(C-c C-x C-b)}}} (~org-toggle-checkbox~) ::

  #+kindex: C-c C-x C-b
  Toggle checkbox status or---with prefix argument---checkbox presence
  at point.  With double prefix argument, set it to =[-]=, which is
  considered to be an intermediate state.

  - If there is an active region, toggle the first checkbox in the
    region and set all remaining boxes to the same status as the
    first.  With a prefix argument, add or remove the checkbox for all
    items in the region.

  - If point is in a headline, toggle checkboxes in the region between
    this headline and the next---so /not/ the entire subtree.

  - If there is no active region, just toggle the checkbox at point.

- {{{kbd(C-c C-x C-r)}}} (~org-toggle-radio-button~) ::

  #+kindex: C-c C-x C-r
  #+findex: org-toggle-radio-button
  #+cindex: radio button, checkbox as
  Toggle checkbox status by using the checkbox of the item at point as
  a radio button: when the checkbox is turned on, all other checkboxes
  on the same level will be turned off.  With a universal prefix
  argument, toggle the presence of the checkbox.  With a double prefix
  argument, set it to =[-]=.

  #+findex: org-list-checkbox-radio-mode
  {{{kbd(C-c C-c)}}} can be told to consider checkboxes as radio buttons by
  setting =#+ATTR_ORG: :radio t= right before the list or by calling
  {{{kbd(M-x org-list-checkbox-radio-mode)}}} to activate this minor mode.

- {{{kbd(M-S-RET)}}} (~org-insert-todo-heading~) ::

  #+kindex: M-S-RET
  #+findex: org-insert-todo-heading
  Insert a new item with a checkbox.  This works only if point is
  already in a plain list item (see [[*Plain Lists]]).

- {{{kbd(C-c C-x o)}}} (~org-toggle-ordered-property~) ::

  #+kindex: C-c C-x o
  #+findex: org-toggle-ordered-property
  #+vindex: org-track-ordered-property-with-tag
  Toggle the =ORDERED= property of the entry, to toggle if checkboxes
  must be checked off in sequence.  A property is used for this
  behavior because this should be local to the current entry, not
  inherited like a tag.  However, if you would like to /track/ the
  value of this property with a tag for better visibility, customize
  ~org-track-ordered-property-with-tag~.

- {{{kbd(C-c #)}}} (~org-update-statistics-cookies~) ::

  #+kindex: C-c #
  #+findex: org-update-statistics-cookies
  Update the statistics cookie in the current outline entry.  When
  called with a {{{kbd(C-u)}}} prefix, update the entire file.
  Checkbox statistic cookies are updated automatically if you toggle
  checkboxes with {{{kbd(C-c C-c)}}} and make new ones with
  {{{kbd(M-S-RET)}}}.  TODO statistics cookies update when changing
  TODO states.  If you delete boxes/entries or add/change them by
  hand, use this command to get things back into sync.

* Tags
:PROPERTIES:
:DESCRIPTION: Tagging headlines and matching sets of tags.
:END:
#+cindex: tags
#+cindex: headline tagging
#+cindex: matching, tags
#+cindex: sparse tree, tag based

An excellent way to implement labels and contexts for
cross-correlating information is to assign /tags/ to headlines.  Org
mode has extensive support for tags.

#+vindex: org-tag-faces
Every headline can contain a list of tags; they occur at the end of
the headline.  Tags are normal words containing letters, numbers, =_=,
and =@=.  Tags must be preceded and followed by a single colon, e.g.,
=:work:=.  Several tags can be specified, as in =:work:urgent:=.  Tags
by default are in bold face with the same color as the headline.  You
may specify special faces for specific tags using the variable
~org-tag-faces~, in much the same way as you can for TODO keywords
(see [[*Faces for TODO keywords]]).

** Tag Inheritance
:PROPERTIES:
:DESCRIPTION: Tags use the tree structure of an outline.
:END:
#+cindex: tag inheritance
#+cindex: inheritance, of tags
#+cindex: sublevels, inclusion into tags match

/Tags/ make use of the hierarchical structure of outline trees.  If
a heading has a certain tag, all subheadings inherit the tag as well.
For example, in the list

#+begin_example
,* Meeting with the French group      :work:
,** Summary by Frank                  :boss:notes:
,*** TODO Prepare slides for him      :action:
#+end_example

#+texinfo: @noindent
the final heading has the tags =work=, =boss=, =notes=, and =action=
even though the final heading is not explicitly marked with those
tags.  You can also set tags that all entries in a file should inherit
just as if these tags were defined in a hypothetical level zero that
surrounds the entire file.  Use a line like this[fn:: As with all
these in-buffer settings, pressing {{{kbd(C-c C-c)}}} activates any
changes in the line.]

#+cindex: @samp{FILETAGS}, keyword
: #+FILETAGS: :Peter:Boss:Secret:

#+vindex: org-use-tag-inheritance
#+vindex: org-tags-exclude-from-inheritance
To limit tag inheritance to specific tags, or to turn it off entirely,
use the variables ~org-use-tag-inheritance~ and
~org-tags-exclude-from-inheritance~.

#+vindex: org-tags-match-list-sublevels
When a headline matches during a tags search while tag inheritance is
turned on, all the sublevels in the same tree---for a simple match
form---match as well[fn:: This is only true if the search does not
involve more complex tests including properties (see [[*Property
Searches]]).].  The list of matches may then become very long.  If you
only want to see the first tags match in a subtree, configure the
variable ~org-tags-match-list-sublevels~ (not recommended).

#+vindex: org-agenda-use-tag-inheritance
Tag inheritance is relevant when the agenda search tries to match
a tag, either in the ~tags~ or ~tags-todo~ agenda types.  In other
agenda types, ~org-use-tag-inheritance~ has no effect.  Still, you may
want to have your tags correctly set in the agenda, so that tag
filtering works fine, with inherited tags.  Set
~org-agenda-use-tag-inheritance~ to control this: the default value
includes all agenda types, but setting this to ~nil~ can really speed
up agenda generation.

** Setting Tags
:PROPERTIES:
:DESCRIPTION: How to assign tags to a headline.
:END:
#+cindex: setting tags
#+cindex: tags, setting

#+kindex: M-TAB
Tags can simply be typed into the buffer at the end of a headline.
After a colon, {{{kbd(M-TAB)}}} offers completion on tags.  There is
also a special command for inserting tags:

- {{{kbd(C-c C-q)}}} (~org-set-tags-command~) ::

  #+kindex: C-c C-q
  #+findex: org-set-tags-command
  #+cindex: completion, of tags
  #+vindex: org-tags-column
  Enter new tags for the current headline.  Org mode either offers
  completion or a special single-key interface for setting tags, see
  below.  After pressing {{{kbd(RET)}}}, the tags are inserted and
  aligned to ~org-tags-column~.  When called with a {{{kbd(C-u)}}}
  prefix, all tags in the current buffer are aligned to that column,
  just to make things look nice.  Tags are automatically realigned
  after promotion, demotion, and TODO state changes (see [[*Basic TODO
  Functionality]]).

- {{{kbd(C-c C-c)}}} (~org-set-tags-command~) ::

  #+kindex: C-c C-c
  When point is in a headline, this does the same as {{{kbd(C-c
  C-q)}}}.

#+vindex: org-complete-tags-always-offer-all-agenda-tags
#+vindex: org-tag-alist
#+cindex: @samp{TAGS}, keyword
Org supports tag insertion based on a /list of tags/.  By default this
list is constructed dynamically, containing all tags currently used in
the buffer[fn:: To extend this default list to all tags used in all
agenda files (see [[*Agenda Views]]), customize the variable
~org-complete-tags-always-offer-all-agenda-tags~.].  You may also
globally specify a hard list of tags with the variable
~org-tag-alist~.  Finally you can set the default tags for a given
file using the =TAGS= keyword, like

#+begin_example
,#+TAGS: @work @home @tennisclub
,#+TAGS: laptop car pc sailboat
#+end_example

If you have globally defined your preferred set of tags using the
variable ~org-tag-alist~, but would like to use a dynamic tag list in
a specific file, add an empty =TAGS= keyword to that file:

: #+TAGS:

#+vindex: org-tag-persistent-alist
If you have a preferred set of tags that you would like to use in
every file, in addition to those defined on a per-file basis by =TAGS=
keyword, then you may specify a list of tags with the variable
~org-tag-persistent-alist~.  You may turn this off on a per-file basis
by adding a =STARTUP= keyword to that file:

: #+STARTUP: noptag

By default Org mode uses the standard minibuffer completion facilities
for entering tags.  However, it also implements another, quicker, tag
selection method called /fast tag selection/.  This allows you to
select and deselect tags with just a single key press.  For this to
work well you should assign unique letters to most of your commonly
used tags.  You can do this globally by configuring the variable
~org-tag-alist~ in your Emacs init file.  For example, you may find
the need to tag many items in different files with =@home=.  In this
case you can set something like:

#+begin_src emacs-lisp
(setq org-tag-alist '(("@work" . ?w) ("@home" . ?h) ("laptop" . ?l)))
#+end_src

If the tag is only relevant to the file you are working on, then you
can instead set the =TAGS= keyword as:

: #+TAGS: @work(w)  @home(h)  @tennisclub(t)  laptop(l)  pc(p)

The tags interface shows the available tags in a splash window.  If
you want to start a new line after a specific tag, insert =\n= into
the tag list

: #+TAGS: @work(w) @home(h) @tennisclub(t) \n laptop(l) pc(p)

#+texinfo: @noindent
or write them in two lines:

#+begin_example
,#+TAGS: @work(w)  @home(h)  @tennisclub(t)
,#+TAGS: laptop(l)  pc(p)
#+end_example

You can also group together tags that are mutually exclusive by using
braces, as in:

: #+TAGS: { @work(w)  @home(h)  @tennisclub(t) }  laptop(l)  pc(p)

#+texinfo: @noindent
you indicate that at most one of =@work=, =@home=, and =@tennisclub=
should be selected.  Multiple such groups are allowed.

Do not forget to press {{{kbd(C-c C-c)}}} with point in one of these
lines to activate any changes.

To set these mutually exclusive groups in the variable
~org-tags-alist~, you must use the dummy tags ~:startgroup~ and
~:endgroup~ instead of the braces.  Similarly, you can use ~:newline~
to indicate a line break.  The previous example would be set globally
by the following configuration:

#+begin_src emacs-lisp
(setq org-tag-alist '((:startgroup . nil)
                      ("@work" . ?w) ("@home" . ?h)
                      ("@tennisclub" . ?t)
                      (:endgroup . nil)
                      ("laptop" . ?l) ("pc" . ?p)))
#+end_src

If at least one tag has a selection key then pressing {{{kbd(C-c
C-c)}}} automatically presents you with a special interface, listing
inherited tags, the tags of the current headline, and a list of all
valid tags with corresponding keys[fn:: Keys are automatically
assigned to tags that have no configured keys.].

Pressing keys assigned to tags adds or removes them from the list of
tags in the current line.  Selecting a tag in a group of mutually
exclusive tags turns off any other tag from that group.

In this interface, you can also use the following special keys:

- {{{kbd(TAB)}}} ::

  #+kindex: TAB
  Enter a tag in the minibuffer, even if the tag is not in the
  predefined list.  You can complete on all tags present in the buffer
  and globally pre-defined tags from ~org-tag-alist~ and
  ~org-tag-persistent-alist~.  You can also add several tags: just
  separate them with a comma.

- {{{kbd(SPC)}}} ::

  #+kindex: SPC
  Clear all tags for this line.

- {{{kbd(RET)}}} ::

  #+kindex: RET
  Accept the modified set.

- {{{kbd(C-g)}}} ::

  #+kindex: C-g
  Abort without installing changes.

- {{{kbd(q)}}} ::

  #+kindex: q
  If {{{kbd(q)}}} is not assigned to a tag, it aborts like
  {{{kbd(C-g)}}}.

- {{{kbd(!)}}} ::

  #+kindex: !
  Turn off groups of mutually exclusive tags.  Use this to (as an
  exception) assign several tags from such a group.

- {{{kbd(C-c)}}} ::

  #+kindex: C-c C-c
  Toggle auto-exit after the next change (see below).  If you are
  using expert mode, the first {{{kbd(C-c)}}} displays the selection
  window.

This method lets you assign tags to a headline with very few keys.
With the above setup, you could clear the current tags and set
=@home=, =laptop= and =pc= tags with just the following keys:
{{{kbd(C-c C-c SPC h l p RET)}}}.  Switching from =@home= to =@work=
would be done with {{{kbd(C-c C-c w RET)}}} or alternatively with
{{{kbd(C-c C-c C-c w)}}}.  Adding the non-predefined tag =sarah= could
be done with {{{kbd(C-c C-c TAB s a r a h RET)}}}.

#+vindex: org-fast-tag-selection-single-key
If you find that most of the time you need only a single key press to
modify your list of tags, set the variable
~org-fast-tag-selection-single-key~.  Then you no longer have to press
{{{kbd(RET)}}} to exit fast tag selection---it exits after the first
change.  If you then occasionally need more keys, press {{{kbd(C-c)}}}
to turn off auto-exit for the current tag selection process (in
effect: start selection with {{{kbd(C-c C-c C-c)}}} instead of
{{{kbd(C-c C-c)}}}).  If you set the variable to the value ~expert~,
the special window is not even shown for single-key tag selection, it
comes up only when you press an extra {{{kbd(C-c)}}}.

** Tag Hierarchy
:PROPERTIES:
:DESCRIPTION: Create a hierarchy of tags.
:END:
#+cindex: group tags
#+cindex: tags, groups
#+cindex: tags hierarchy

Tags can be defined in hierarchies.  A tag can be defined as a /group
tag/ for a set of other tags.  The group tag can be seen as the
"broader term" for its set of tags.  Defining multiple group tags and
nesting them creates a tag hierarchy.

One use-case is to create a taxonomy of terms (tags) that can be used
to classify nodes in a document or set of documents.

When you search for a group tag, it return matches for all members in
the group and its subgroups.  In an agenda view, filtering by a group
tag displays or hide headlines tagged with at least one of the members
of the group or any of its subgroups.  This makes tag searches and
filters even more flexible.

You can set group tags by using brackets and inserting a colon between
the group tag and its related tags---beware that all whitespaces are
mandatory so that Org can parse this line correctly:

: #+TAGS: [ GTD : Control Persp ]

In this example, =GTD= is the group tag and it is related to two other
tags: =Control=, =Persp=.  Defining =Control= and =Persp= as group
tags creates a hierarchy of tags:

#+begin_example
,#+TAGS: [ Control : Context Task ]
,#+TAGS: [ Persp : Vision Goal AOF Project ]
#+end_example

That can conceptually be seen as a hierarchy of tags:

- =GTD=
  - =Persp=
    - =Vision=
    - =Goal=
    - =AOF=
    - =Project=
  - =Control=
    - =Context=
    - =Task=

You can use the ~:startgrouptag~, ~:grouptags~ and ~:endgrouptag~
keyword directly when setting ~org-tag-alist~ directly:

#+begin_src emacs-lisp
(setq org-tag-alist '((:startgrouptag)
                      ("GTD")
                      (:grouptags)
                      ("Control")
                      ("Persp")
                      (:endgrouptag)
                      (:startgrouptag)
                      ("Control")
                      (:grouptags)
                      ("Context")
                      ("Task")
                      (:endgrouptag)))
#+end_src

The tags in a group can be mutually exclusive if using the same group
syntax as is used for grouping mutually exclusive tags together; using
curly brackets.

: #+TAGS: { Context : @Home @Work @Call }

When setting ~org-tag-alist~ you can use ~:startgroup~ and ~:endgroup~
instead of ~:startgrouptag~ and ~:endgrouptag~ to make the tags
mutually exclusive.

Furthermore, the members of a group tag can also be regular
expressions, creating the possibility of a more dynamic and rule-based
tag structure (see [[*Regular Expressions]]).  The regular expressions in
the group must be specified within curly brackets.  Here is an
expanded example:

#+begin_example
,#+TAGS: [ Vision : {V@.+} ]
,#+TAGS: [ Goal : {G@.+} ]
,#+TAGS: [ AOF : {AOF@.+} ]
,#+TAGS: [ Project : {P@.+} ]
#+end_example

Searching for the tag =Project= now lists all tags also including
regular expression matches for =P@.+=, and similarly for tag searches
on =Vision=, =Goal= and =AOF=.  For example, this would work well for
a project tagged with a common project-identifier, e.g.,
=P@2014_OrgTags=.

#+kindex: C-c C-x q
#+findex: org-toggle-tags-groups
#+vindex: org-group-tags
If you want to ignore group tags temporarily, toggle group tags
support with ~org-toggle-tags-groups~, bound to {{{kbd(C-c C-x q)}}}.
If you want to disable tag groups completely, set ~org-group-tags~ to
~nil~.

** Tag Searches
:PROPERTIES:
:DESCRIPTION: Searching for combinations of tags.
:END:
#+cindex: tag searches
#+cindex: searching for tags

Once a system of tags has been set up, it can be used to collect
related information into special lists.

- {{{kbd(C-c / m)}}} or {{{kbd(C-c \)}}} (~org-match-sparse-tree~) ::

  #+kindex: C-c / m
  #+kindex: C-c \
  #+findex: org-match-sparse-tree
  Create a sparse tree with all headlines matching a tags search.
  With a {{{kbd(C-u)}}} prefix argument, ignore headlines that are not
  a TODO line.

- {{{kbd(M-x org-agenda m)}}} (~org-tags-view~) ::

  #+kindex: m @r{(Agenda dispatcher)}
  #+findex: org-tags-view
  Create a global list of tag matches from all agenda files.  See
  [[*Matching tags and properties]].

- {{{kbd(M-x org-agenda M)}}} (~org-tags-view~) ::

  #+kindex: M @r{(Agenda dispatcher)}
  #+vindex: org-tags-match-list-sublevels
  Create a global list of tag matches from all agenda files, but check
  only TODO items and force checking subitems (see the option
  ~org-tags-match-list-sublevels~).

These commands all prompt for a match string which allows basic
Boolean logic like =+boss+urgent-project1=, to find entries with tags
=boss= and =urgent=, but not =project1=, or =Kathy|Sally= to find
entries which are tagged, like =Kathy= or =Sally=.  The full syntax of
the search string is rich and allows also matching against TODO
keywords, entry levels and properties.  For a complete description
with many examples, see [[*Matching tags and properties]].

* Properties and Columns
:PROPERTIES:
:DESCRIPTION: Storing information about an entry.
:END:
#+cindex: properties

A property is a key-value pair associated with an entry.  Properties
can be set so they are associated with a single entry, with every
entry in a tree, or with the whole buffer.

There are two main applications for properties in Org mode.  First,
properties are like tags, but with a value.  Imagine maintaining
a file where you document bugs and plan releases for a piece of
software.  Instead of using tags like =release_1=, =release_2=, you
can use a property, say =Release=, that in different subtrees has
different values, such as =1.0= or =2.0=.  Second, you can use
properties to implement (very basic) database capabilities in an Org
buffer.  Imagine keeping track of your music CDs, where properties
could be things such as the album, artist, date of release, number of
tracks, and so on.

Properties can be conveniently edited and viewed in column view (see
[[*Column View]]).

** Property Syntax
:PROPERTIES:
:DESCRIPTION: How properties are spelled out.
:END:
#+cindex: property syntax
#+cindex: drawer, for properties

Properties are key--value pairs.  When they are associated with
a single entry or with a tree they need to be inserted into a special
drawer (see [[*Drawers]]) with the name =PROPERTIES=, which has to be
located right below a headline, and its planning line (see [[*Deadlines
and Scheduling]]) when applicable.  Each property is specified on
a single line, with the key---surrounded by colons---first, and the
value after it.  Keys are case-insensitive.  Here is an example:

#+begin_example
,* CD collection
,** Classic
,*** Goldberg Variations
    :PROPERTIES:
    :Title:     Goldberg Variations
    :Composer:  J.S. Bach
    :Artist:    Glenn Gould
    :Publisher: Deutsche Grammophon
    :NDisks:    1
    :END:
#+end_example

Depending on the value of ~org-use-property-inheritance~, a property
set this way is associated either with a single entry, or with the
subtree defined by the entry, see [[*Property Inheritance]].

You may define the allowed values for a particular property =Xyz= by
setting a property =Xyz_ALL=.  This special property is /inherited/,
so if you set it in a level 1 entry, it applies to the entire tree.
When allowed values are defined, setting the corresponding property
becomes easier and is less prone to typing errors.  For the example
with the CD collection, we can pre-define publishers and the number of
disks in a box like this:

#+begin_example
,* CD collection
  :PROPERTIES:
  :NDisks_ALL:  1 2 3 4
  :Publisher_ALL: "Deutsche Grammophon" Philips EMI
  :END:
#+end_example

Properties can be inserted on buffer level.  That means they apply
before the first headline and can be inherited by all entries in a
file.  Property blocks defined before first headline needs to be
located at the top of the buffer, allowing only comments above.

Properties can also be defined using lines like:

#+cindex: @samp{_ALL} suffix, in properties
#+cindex: @samp{PROPERTY}, keyword
: #+PROPERTY: NDisks_ALL 1 2 3 4

#+cindex: @samp{+} suffix, in properties
If you want to add to the value of an existing property, append a =+=
to the property name.  The following results in the property =var=
having the value =foo=1 bar=2=.

#+begin_example
,#+PROPERTY: var  foo=1
,#+PROPERTY: var+ bar=2
#+end_example

It is also possible to add to the values of inherited properties.  The
following results in the =Genres= property having the value =Classic
Baroque= under the =Goldberg Variations= subtree.

#+begin_example
,* CD collection
,** Classic
    :PROPERTIES:
    :Genres: Classic
    :END:
,*** Goldberg Variations
    :PROPERTIES:
    :Title:     Goldberg Variations
    :Composer:  J.S. Bach
    :Artist:    Glenn Gould
    :Publisher: Deutsche Grammophon
    :NDisks:    1
    :Genres+:   Baroque
    :END:
#+end_example

Note that a property can only have one entry per drawer.

#+vindex: org-global-properties
Property values set with the global variable ~org-global-properties~
can be inherited by all entries in all Org files.

The following commands help to work with properties:

#+attr_texinfo: :sep ,
- {{{kbd(M-TAB)}}} (~pcomplete~) ::

  #+kindex: M-TAB
  #+findex: pcomplete
  After an initial colon in a line, complete property keys.  All keys
  used in the current file are offered as possible completions.

- {{{kbd(C-c C-x p)}}} (~org-set-property~) ::

  #+kindex: C-c C-x p
  #+findex: org-set-property
  Set a property.  This prompts for a property name and a value.  If
  necessary, the property drawer is created as well.

- {{{kbd(C-u M-x org-insert-drawer)}}} ::

  #+findex: org-insert-drawer
  Insert a property drawer into the current entry.  The drawer is
  inserted early in the entry, but after the lines with planning
  information like deadlines.  If before first headline the drawer is
  inserted at the top of the drawer after any potential comments.

- {{{kbd(C-c C-c)}}} (~org-property-action~) ::

  #+kindex: C-c C-c
  #+findex: org-property-action
  With point in a property drawer, this executes property commands.

- {{{kbd(C-c C-c s)}}} (~org-set-property~) ::

  #+kindex: C-c C-c s
  #+findex: org-set-property
  Set a property in the current entry.  Both the property and the
  value can be inserted using completion.

- {{{kbd(S-RIGHT)}}} (~org-property-next-allowed-value~),  {{{kbd(S-LEFT)}}} (~org-property-previous-allowed-value~) ::

  #+kindex: S-RIGHT
  #+kindex: S-LEFT
  Switch property at point to the next/previous allowed value.

- {{{kbd(C-c C-c d)}}} (~org-delete-property~) ::

  #+kindex: C-c C-c d
  #+findex: org-delete-property
  Remove a property from the current entry.

- {{{kbd(C-c C-c D)}}} (~org-delete-property-globally~) ::

  #+kindex: C-c C-c D
  #+findex: org-delete-property-globally
  Globally remove a property, from all entries in the current file.

- {{{kbd(C-c C-c c)}}} (~org-compute-property-at-point~) ::

  #+kindex: C-c C-c c
  #+findex: org-compute-property-at-point
  Compute the property at point, using the operator and scope from the
  nearest column format definition.

** Special Properties
:PROPERTIES:
:DESCRIPTION: Access to other Org mode features.
:END:
#+cindex: properties, special

Special properties provide an alternative access method to Org mode
features, like the TODO state or the priority of an entry, discussed
in the previous chapters.  This interface exists so that you can
include these states in a column view (see [[*Column View]]), or to use
them in queries.  The following property names are special and should
not be used as keys in the properties drawer:

#+cindex: @samp{ALLTAGS}, special property
#+cindex: @samp{BLOCKED}, special property
#+cindex: @samp{CLOCKSUM}, special property
#+cindex: @samp{CLOCKSUM_T}, special property
#+cindex: @samp{CLOSED}, special property
#+cindex: @samp{DEADLINE}, special property
#+cindex: @samp{FILE}, special property
#+cindex: @samp{ITEM}, special property
#+cindex: @samp{PRIORITY}, special property
#+cindex: @samp{SCHEDULED}, special property
#+cindex: @samp{TAGS}, special property
#+cindex: @samp{TIMESTAMP}, special property
#+cindex: @samp{TIMESTAMP_IA}, special property
#+cindex: @samp{TODO}, special property
| =ALLTAGS=      | All tags, including inherited ones.                            |
| =BLOCKED=      | ~t~ if task is currently blocked by children or siblings.      |
| =CATEGORY=     | The category of an entry.                                      |
| =CLOCKSUM=     | The sum of CLOCK intervals in the subtree.  ~org-clock-sum~    |
|                | must be run first to compute the values in the current buffer. |
| =CLOCKSUM_T=   | The sum of CLOCK intervals in the subtree for today.           |
|                | ~org-clock-sum-today~ must be run first to compute the         |
|                | values in the current buffer.                                  |
| =CLOSED=       | When was this entry closed?                                    |
| =DEADLINE=     | The deadline timestamp.                                        |
| =FILE=         | The filename the entry is located in.                          |
| =ITEM=         | The headline of the entry.                                     |
| =PRIORITY=     | The priority of the entry, a string with a single letter.      |
| =SCHEDULED=    | The scheduling timestamp.                                      |
| =TAGS=         | The tags defined directly in the headline.                     |
| =TIMESTAMP=    | The first keyword-less timestamp in the entry.                 |
| =TIMESTAMP_IA= | The first inactive timestamp in the entry.                     |
| =TODO=         | The TODO keyword of the entry.                                 |

** Property Searches
:PROPERTIES:
:DESCRIPTION: Matching property values.
:END:
#+cindex: properties, searching
#+cindex: searching, of properties

To create sparse trees and special lists with selection based on
properties, the same commands are used as for tag searches (see [[*Tag
Searches]]).

- {{{kbd(C-c / m)}}} or {{{kbd(C-c \)}}} (~org-match-sparse-tree~) ::

  #+kindex: C-c / m
  #+kindex: C-c \
  #+findex: org-match-sparse-tree
  Create a sparse tree with all matching entries.  With
  a {{{kbd(C-u)}}} prefix argument, ignore headlines that are not
  a TODO line.

- {{{kbd(M-x org-agenda m)}}} (~org-tags-view~) ::

  #+kindex: m @r{(Agenda dispatcher)}
  #+findex: org-tags-view
  Create a global list of tag/property matches from all agenda files.

- {{{kbd(M-x org-agenda M)}}} (~org-tags-view~) ::

  #+kindex: M @r{(Agenda dispatcher)}
  #+vindex: org-tags-match-list-sublevels
  Create a global list of tag matches from all agenda files, but check
  only TODO items and force checking of subitems (see the option
  ~org-tags-match-list-sublevels~).

The syntax for the search string is described in [[*Matching tags and
properties]].

There is also a special command for creating sparse trees based on a
single property:

- {{{kbd(C-c / p)}}} ::

  #+kindex: C-c / p
  Create a sparse tree based on the value of a property.  This first
  prompts for the name of a property, and then for a value.  A sparse
  tree is created with all entries that define this property with the
  given value.  If you enclose the value in curly braces, it is
  interpreted as a regular expression and matched against the property
  values (see [[*Regular Expressions]]).

** Property Inheritance
:PROPERTIES:
:DESCRIPTION: Passing values down a tree.
:END:
#+cindex: properties, inheritance
#+cindex: inheritance, of properties

#+vindex: org-use-property-inheritance
The outline structure of Org documents lends itself to an inheritance
model of properties: if the parent in a tree has a certain property,
the children can inherit this property.  Org mode does not turn this
on by default, because it can slow down property searches
significantly and is often not needed.  However, if you find
inheritance useful, you can turn it on by setting the variable
~org-use-property-inheritance~.  It may be set to ~t~ to make all
properties inherited from the parent, to a list of properties that
should be inherited, or to a regular expression that matches inherited
properties.  If a property has the value ~nil~, this is interpreted as
an explicit un-define of the property, so that inheritance search
stops at this value and returns ~nil~.

Org mode has a few properties for which inheritance is hard-coded, at
least for the special applications for which they are used:

- ~COLUMNS~ ::

  #+cindex: @samp{COLUMNS}, property
  The =COLUMNS= property defines the format of column view (see
  [[*Column View]]).  It is inherited in the sense that the level where
  a =COLUMNS= property is defined is used as the starting point for
  a column view table, independently of the location in the subtree
  from where columns view is turned on.

- ~CATEGORY~ ::

  #+cindex: @samp{CATEGORY}, property
  For agenda view, a category set through a =CATEGORY= property
  applies to the entire subtree.

- ~ARCHIVE~ ::

  #+cindex: @samp{ARCHIVE}, property
  For archiving, the =ARCHIVE= property may define the archive
  location for the entire subtree (see [[*Moving a tree to an archive
  file]]).

- ~LOGGING~ ::

  #+cindex: @samp{LOGGING}, property
  The =LOGGING= property may define logging settings for an entry or
  a subtree (see [[*Tracking TODO state changes]]).

** Column View
:PROPERTIES:
:DESCRIPTION: Tabular viewing and editing.
:END:

A great way to view and edit properties in an outline tree is /column
view/.  In column view, each outline node is turned into a table row.
Columns in this table provide access to properties of the entries.
Org mode implements columns by overlaying a tabular structure over the
headline of each item.  While the headlines have been turned into
a table row, you can still change the visibility of the outline tree.
For example, you get a compact table by switching to "contents"
view---{{{kbd(S-TAB)}}} {{{kbd(S-TAB)}}}, or simply {{{kbd(c)}}}
while column view is active---but you can still open, read, and edit
the entry below each headline.  Or, you can switch to column view
after executing a sparse tree command and in this way get a table only
for the selected items.  Column view also works in agenda buffers (see
[[*Agenda Views]]) where queries have collected selected items, possibly
from a number of files.

*** Defining columns
:PROPERTIES:
:DESCRIPTION: The COLUMNS format property.
:END:
#+cindex: column view, for properties
#+cindex: properties, column view

Setting up a column view first requires defining the columns.  This is
done by defining a column format line.

**** Scope of column definitions
:PROPERTIES:
:DESCRIPTION: Where defined, where valid?
:END:

To specify a format that only applies to a specific tree, add
a =COLUMNS= property to the top node of that tree, for example:

#+begin_example
,** Top node for columns view
   :PROPERTIES:
   :COLUMNS: %25ITEM %TAGS %PRIORITY %TODO
   :END:
#+end_example

A =COLUMNS= property within a property drawer before first headline
will apply to the entire file.  As an addition to property drawers,
keywords can also be defined for an entire file using a line like:

#+cindex: @samp{COLUMNS}, keyword
: #+COLUMNS: %25ITEM %TAGS %PRIORITY %TODO

If a =COLUMNS= property is present in an entry, it defines columns for
the entry itself, and for the entire subtree below it.  Since the
column definition is part of the hierarchical structure of the
document, you can define columns on level 1 that are general enough
for all sublevels, and more specific columns further down, when you
edit a deeper part of the tree.

**** Column attributes
:PROPERTIES:
:DESCRIPTION: Appearance and content of a column.
:END:

A column definition sets the attributes of a column.  The general
definition looks like this:

: %[WIDTH]PROPERTY[(TITLE)][{SUMMARY-TYPE}]

#+texinfo: @noindent
Except for the percent sign and the property name, all items are
optional.  The individual parts have the following meaning:

- {{{var(WIDTH)}}} ::

  An integer specifying the width of the column in characters.  If
  omitted, the width is determined automatically.

- {{{var(PROPERTY)}}} ::

  The property that should be edited in this column.  Special
  properties representing meta data are allowed here as well (see
  [[*Special Properties]]).

- {{{var(TITLE)}}} ::

  The header text for the column.  If omitted, the property name is
  used.

- {{{var(SUMMARY-TYPE)}}} ::

  The summary type.  If specified, the column values for parent nodes
  are computed from the children[fn:: If more than one summary type
  applies to the same property, the parent values are computed
  according to the first of them.].

  Supported summary types are:

  | =+=      | Sum numbers in this column.                           |
  | =+;%.1f= | Like =+=, but format result with =%.1f=.              |
  | =$=      | Currency, short for =+;%.2f=.                         |
  | =min=    | Smallest number in column.                            |
  | =max=    | Largest number.                                       |
  | =mean=   | Arithmetic mean of numbers.                           |
  | =X=      | Checkbox status, =[X]= if all children are =[X]=.     |
  | =X/=     | Checkbox status, =[n/m]=.                             |
  | =X%=     | Checkbox status, =[n%]=.                              |
  | =:=      | Sum times, HH:MM, plain numbers are minutes.          |
  | =:min=   | Smallest time value in column.                        |
  | =:max=   | Largest time value.                                   |
  | =:mean=  | Arithmetic mean of time values.                       |
  | =@min=   | Minimum age[fn:18] (in days/hours/mins/seconds).      |
  | =@max=   | Maximum age (in days/hours/mins/seconds).             |
  | =@mean=  | Arithmetic mean of ages (in days/hours/mins/seconds). |
  | =est+=   | Add low-high estimates.                               |

  #+vindex: org-columns-summary-types
  You can also define custom summary types by setting
  ~org-columns-summary-types~.

The =est+= summary type requires further explanation.  It is used for
combining estimates, expressed as low-high ranges.  For example,
instead of estimating a particular task will take 5 days, you might
estimate it as 5--6 days if you're fairly confident you know how much
work is required, or 1--10 days if you do not really know what needs
to be done.  Both ranges average at 5.5 days, but the first represents
a more predictable delivery.

When combining a set of such estimates, simply adding the lows and
highs produces an unrealistically wide result.  Instead, =est+= adds
the statistical mean and variance of the subtasks, generating a final
estimate from the sum.  For example, suppose you had ten tasks, each
of which was estimated at 0.5 to 2 days of work.  Straight addition
produces an estimate of 5 to 20 days, representing what to expect if
everything goes either extremely well or extremely poorly.  In
contrast, =est+= estimates the full job more realistically, at 10--15
days.

Here is an example for a complete columns definition, along with
allowed values[fn:: Please note that the =COLUMNS= definition must be
on a single line; it is wrapped here only because of formatting
constraints.].

#+begin_example
:COLUMNS:  %25ITEM %9Approved(Approved?){X} %Owner %11Status \
                   %10Time_Estimate{:} %CLOCKSUM %CLOCKSUM_T
:Owner_ALL:    Tammy Mark Karl Lisa Don
:Status_ALL:   "In progress" "Not started yet" "Finished" ""
:Approved_ALL: "[ ]" "[X]"
#+end_example

#+texinfo: @noindent
The first column, =%25ITEM=, means the first 25 characters of the item
itself, i.e., of the headline.  You probably always should start the
column definition with the =ITEM= specifier.  The other specifiers
create columns =Owner= with a list of names as allowed values, for
=Status= with four different possible values, and for a checkbox field
=Approved=.  When no width is given after the =%= character, the
column is exactly as wide as it needs to be in order to fully display
all values.  The =Approved= column does have a modified title
(=Approved?=, with a question mark).  Summaries are created for the
=Time_Estimate= column by adding time duration expressions like HH:MM,
and for the =Approved= column, by providing an =[X]= status if all
children have been checked.  The =CLOCKSUM= and =CLOCKSUM_T= columns
are special, they lists the sums of CLOCK intervals in the subtree,
either for all clocks or just for today.

*** Using column view
:PROPERTIES:
:DESCRIPTION: How to create and use column view.
:END:

**** Turning column view on or off
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- {{{kbd(C-c C-x C-c)}}} (~org-columns~) ::

  #+kindex: C-c C-x C-c
  #+vindex: org-columns
  #+vindex: org-columns-default-format
  Turn on column view.  If point is before the first headline in the
  file, column view is turned on for the entire file, using the
  =#+COLUMNS= definition.  If point is somewhere inside the outline,
  this command searches the hierarchy, up from point, for a =COLUMNS=
  property that defines a format.  When one is found, the column view
  table is established for the tree starting at the entry that
  contains the =COLUMNS= property.  If no such property is found, the
  format is taken from the =#+COLUMNS= line or from the variable
  ~org-columns-default-format~, and column view is established for the
  current entry and its subtree.

- {{{kbd(r)}}} or {{{kbd(g)}}} on a columns view line (~org-columns-redo~) ::

  #+kindex: r
  #+kindex: g
  #+findex: org-columns-redo
  Recreate the column view, to include recent changes made in the
  buffer.

- {{{kbd(C-c C-c)}}} or {{{kbd(q)}}} on a columns view line (~org-columns-quit~) ::

  #+kindex: q
  #+kindex: C-c C-c
  #+findex: org-columns-quit
  Exit column view.

**** Editing values
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+attr_texinfo: :sep and
- {{{kbd(LEFT)}}}, {{{kbd(RIGHT)}}}, {{{kbd(UP)}}}, {{{kbd(DOWN)}}} ::

  Move through the column view from field to field.

- {{{kbd(1..9\,0)}}} ::

  #+kindex: 1..9,0
  Directly select the Nth allowed value, {{{kbd(0)}}} selects the
  10th value.

- {{{kbd(n)}}} or {{{kbd(S-RIGHT)}}} (~org-columns-next-allowed-value~) and {{{kbd(p)}}} or {{{kbd(S-LEFT)}}} (~org-columns-previous-allowed-value~) ::

  #+kindex: n
  #+kindex: S-RIGHT
  #+kindex: p
  #+kindex: S-LEFT
  #+findex: org-columns-next-allowed-value
  #+findex: org-columns-previous-allowed-value
  Switch to the next/previous allowed value of the field.  For this,
  you have to have specified allowed values for a property.

- {{{kbd(e)}}} (~org-columns-edit-value~) ::

  #+kindex: e
  #+findex: org-columns-edit-value
  Edit the property at point.  For the special properties, this
  invokes the same interface that you normally use to change that
  property.  For example, the tag completion or fast selection
  interface pops up when editing a =TAGS= property.

- {{{kbd(C-c C-c)}}} (~org-columns-toggle-or-columns-quit~) ::

  #+kindex: C-c C-c
  #+findex: org-columns-toggle-or-columns-quit
  When there is a checkbox at point, toggle it.  Else exit column
  view.

- {{{kbd(v)}}} (~org-columns-show-value~) ::

  #+kindex: v
  #+findex: org-columns-show-value
  View the full value of this property.  This is useful if the width
  of the column is smaller than that of the value.

- {{{kbd(a)}}} (~org-columns-edit-allowed~) ::

  #+kindex: a
  #+findex: org-columns-edit-allowed
  Edit the list of allowed values for this property.  If the list is
  found in the hierarchy, the modified values is stored there.  If no
  list is found, the new value is stored in the first entry that is
  part of the current column view.

**** Modifying column view on-the-fly
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+attr_texinfo: :sep and
- {{{kbd(<)}}} (~org-columns-narrow~) and {{{kbd(>)}}} (~org-columns-widen~) ::

  #+kindex: <
  #+kindex: >
  #+findex: org-columns-narrow
  #+findex: org-columns-widen
  Make the column narrower/wider by one character.

- {{{kbd(S-M-RIGHT)}}} (~org-columns-new~) ::

  #+kindex: S-M-RIGHT
  #+findex: org-columns-new
  Insert a new column, to the left of the current column.

- {{{kbd(S-M-LEFT)}}} (~org-columns-delete~) ::

  #+kindex: S-M-LEFT
  #+findex: org-columns-delete
  Delete the current column.

*** Capturing column view
:PROPERTIES:
:DESCRIPTION: A dynamic block for column view.
:END:

Since column view is just an overlay over a buffer, it cannot be
exported or printed directly.  If you want to capture a column view,
use a =columnview= dynamic block (see [[*Dynamic Blocks]]).  The frame of
this block looks like this:

#+cindex: @samp{BEGIN columnview}
#+begin_example
,* The column view
,#+BEGIN: columnview :hlines 1 :id "label"

,#+END:
#+end_example

This dynamic block has the following parameters:

- =:id= ::

  This is the most important parameter.  Column view is a feature that
  is often localized to a certain (sub)tree, and the capture block
  might be at a different location in the file.  To identify the tree
  whose view to capture, you can use four values:

  - =local= ::

    Use the tree in which the capture block is located.

  - =global= ::

    Make a global view, including all headings in the file.

  - =file:FILENAME= ::

    Run column view at the top of the {{{var(FILENAME)}}} file.

  - =LABEL= ::

    #+cindex: @samp{ID}, property
    Call column view in the tree that has an =ID= property with the
    value {{{var(LABEL)}}}.  You can use {{{kbd(M-x org-id-copy)}}} to
    create a globally unique ID for the current entry and copy it to
    the kill-ring.

- =:match= ::

  When set to a string, use this as a tags/property match filter to
  select only a subset of the headlines in the scope set by the ~:id~
  parameter.


- =:hlines= ::

  When ~t~, insert an hline after every line.  When a number N, insert
  an hline before each headline with level ~<= N~.

- =:vlines= ::

  When non-~nil~, force column groups to get vertical lines.

- =:maxlevel= ::

  When set to a number, do not capture entries below this level.

- =:skip-empty-rows= ::

  When non-~nil~, skip rows where the only non-empty specifier of
  the column view is =ITEM=.

- =:exclude-tags= ::

  List of tags to exclude from column view table: entries with these
  tags will be excluded from the column view.

- =:indent= ::

  When non-~nil~, indent each =ITEM= field according to its level.

- =:format= ::

  Specify a column attribute (see [[*Column attributes]]) for the dynamic
  block.

The following commands insert or update the dynamic block:

- ~org-columns-insert-dblock~ ::

  #+kindex: C-c C-x x
  #+findex: org-columns-insert-dblock
  Insert a dynamic block capturing a column view.  Prompt for the
  scope or ID of the view.

  This command can be invoked by calling
  ~org-dynamic-block-insert-dblock~ ({{{kbd(C-c C-x x)}}}) and
  selecting "columnview" (see [[*Dynamic Blocks]]).

- {{{kbd(C-c C-c)}}} {{{kbd(C-c C-x C-u)}}} (~org-dblock-update~) ::

  #+kindex: C-c C-c
  #+kindex: C-c C-x C-u
  #+findex: org-dblock-update
  Update dynamic block at point.  point needs to be in the =#+BEGIN=
  line of the dynamic block.

- {{{kbd(C-u C-c C-x C-u)}}} (~org-update-all-dblocks~) ::

  #+kindex: C-u C-c C-x C-u
  Update all dynamic blocks (see [[*Dynamic Blocks]]).  This is useful if
  you have several clock table blocks, column-capturing blocks or
  other dynamic blocks in a buffer.

You can add formulas to the column view table and you may add plotting
instructions in front of the table---these survive an update of the
block.  If there is a =TBLFM= keyword after the table, the table is
recalculated automatically after an update.

An alternative way to capture and process property values into a table
is provided by Eric Schulte's =org-collector.el=, which is a package
in =org-contrib=[fn:: Contributed packages are not part of Emacs, but
are distributed with the main distribution of Org---visit
[[https://orgmode.org]].].  It provides a general API to collect
properties from entries in a certain scope, and arbitrary Lisp
expressions to process these values before inserting them into a table
or a dynamic block.

* Dates and Times
:PROPERTIES:
:DESCRIPTION: Making items useful for planning.
:END:
#+cindex: dates
#+cindex: times
#+cindex: timestamp
#+cindex: date stamp

To assist project planning, TODO items can be labeled with a date
and/or a time.  The specially formatted string carrying the date and
time information is called a /timestamp/ in Org mode.  This may be
a little confusing because timestamp is often used as indicating when
something was created or last changed.  However, in Org mode this term
is used in a much wider sense.

** Timestamps
:PROPERTIES:
:DESCRIPTION: Assigning a time to a tree entry.
:END:
#+cindex: timestamps
#+cindex: ranges, time
#+cindex: date stamps
#+cindex: deadlines
#+cindex: scheduling

A timestamp is a specification of a date (possibly with a time or
a range of times) in a special format, either =<2003-09-16 Tue>= or
=<2003-09-16 Tue 09:39>= or =<2003-09-16 Tue 12:00-12:30>=[fn:19].
A timestamp can appear anywhere in the headline or body of an Org tree
entry.  Its presence causes entries to be shown on specific dates in
the agenda (see [[*Weekly/daily agenda]]).  We distinguish:

- Plain timestamp; Event; Appointment ::

  #+cindex: timestamp
  #+cindex: appointment
  A simple timestamp just assigns a date/time to an item.  This is
  just like writing down an appointment or event in a paper agenda.
  In the agenda display, the headline of an entry associated with
  a plain timestamp is shown exactly on that date.

  #+begin_example
  ,* Meet Peter at the movies
    <2006-11-01 Wed 19:15>
  ,* Discussion on climate change
    <2006-11-02 Thu 20:00-22:00>
  #+end_example

- Timestamp with repeater interval ::

  #+cindex: timestamp, with repeater interval
  A timestamp may contain a /repeater interval/, indicating that it
  applies not only on the given date, but again and again after
  a certain interval of N hours (h), days (d), weeks (w), months (m),
  or years (y).  The following shows up in the agenda every Wednesday:

  #+begin_example
  ,* Pick up Sam at school
    <2007-05-16 Wed 12:30 +1w>
  #+end_example

- Diary-style expression entries ::

  #+cindex: diary style timestamps
  #+cindex: sexp timestamps
  # Mentioned inside the footnote.
  #+findex: org-date
  #+findex: org-anniversary
  #+findex: org-cyclic
  #+findex: org-block

  For more complex date specifications, Org mode supports using the
  special expression diary entries implemented in the Emacs Calendar
  package[fn:20].  For example, with optional time:

  #+begin_example
  ,* 22:00-23:00 The nerd meeting on every 2nd Thursday of the month
    <%%(diary-float t 4 2)>
  #+end_example

- Time/Date range ::

  #+cindex: timerange
  #+cindex: date range
  Two timestamps connected by =--= denote a range.  The headline is
  shown on the first and last day of the range, and on any dates that
  are displayed and fall in the range.  Here is an example:

  #+begin_example
  ,** Meeting in Amsterdam
     <2004-08-23 Mon>--<2004-08-26 Thu>
  #+end_example

- Inactive timestamp ::

  #+cindex: timestamp, inactive
  #+cindex: inactive timestamp
  Just like a plain timestamp, but with square brackets instead of
  angular ones.  These timestamps are inactive in the sense that they
  do /not/ trigger an entry to show up in the agenda.

  #+begin_example
  ,* Gillian comes late for the fifth time
    [2006-11-01 Wed]
  #+end_example

** Creating Timestamps
:PROPERTIES:
:DESCRIPTION: Commands to insert timestamps.
:END:

For Org mode to recognize timestamps, they need to be in the specific
format.  All commands listed below produce timestamps in the correct
format.

#+attr_texinfo: :sep ,
- {{{kbd(C-c .)}}} (~org-time-stamp~) ::

  #+kindex: C-c .
  #+findex: org-time-stamp
  Prompt for a date and insert a corresponding timestamp.  When point
  is at an existing timestamp in the buffer, the command is used to
  modify this timestamp instead of inserting a new one.  When this
  command is used twice in succession, a time range is inserted.

  #+kindex: C-u C-c .
  #+vindex: org-time-stamp-rounding-minutes
  When called with a prefix argument, use the alternative format which
  contains date and time.  The default time can be rounded to
  multiples of 5 minutes.  See the option
  ~org-time-stamp-rounding-minutes~.

  #+kindex: C-u C-u C-c .
  With two prefix arguments, insert an active timestamp with the
  current time without prompting.

- {{{kbd(C-c !)}}} (~org-time-stamp-inactive~) ::

  #+kindex: C-c !
  #+kindex: C-u C-c !
  #+kindex: C-u C-u C-c !
  #+findex: org-time-stamp-inactive
  Like {{{kbd(C-c .)}}}, but insert an inactive timestamp that does
  not cause an agenda entry.

- {{{kbd(C-c C-c)}}} ::

  #+kindex: C-c C-c
  Normalize timestamp, insert or fix day name if missing or wrong.

- {{{kbd(C-c <)}}} (~org-date-from-calendar~) ::

  #+kindex: C-c <
  #+findex: org-date-from-calendar
  Insert a timestamp corresponding to point date in the calendar.

- {{{kbd(C-c >)}}} (~org-goto-calendar~) ::

  #+kindex: C-c >
  #+findex: org-goto-calendar
  Access the Emacs calendar for the current date.  If there is
  a timestamp in the current line, go to the corresponding date
  instead.

- {{{kbd(C-c C-o)}}} (~org-open-at-point~) ::

  #+kindex: C-c C-o
  #+findex: org-open-at-point
  Access the agenda for the date given by the timestamp or -range at
  point (see [[*Weekly/daily agenda]]).

- {{{kbd(S-LEFT)}}} (~org-timestamp-down-day~), {{{kbd(S-RIGHT)}}} (~org-timestamp-up-day~) ::

  #+kindex: S-LEFT
  #+kindex: S-RIGHT
  #+findex: org-timestamp-down-day
  #+findex: org-timestamp-up-day
  Change date at point by one day.  These key bindings conflict with
  shift-selection and related modes (see [[*Packages that conflict with
  Org mode]]).

- {{{kbd(S-UP)}}} (~org-timestamp-up~), {{{kbd(S-DOWN)}}} (~org-timestamp-down~) ::

  #+kindex: S-UP
  #+kindex: S-DOWN
  On the beginning or enclosing bracket of a timestamp, change its
  type.  Within a timestamp, change the item under point.  Point can
  be on a year, month, day, hour or minute.  When the timestamp
  contains a time range like =15:30-16:30=, modifying the first time
  also shifts the second, shifting the time block with constant
  length.  To change the length, modify the second time.  Note that if
  point is in a headline and not at a timestamp, these same keys
  modify the priority of an item (see [[*Priorities]]).  The key bindings
  also conflict with shift-selection and related modes (see [[*Packages
  that conflict with Org mode]]).

- {{{kbd(C-c C-y)}}} (~org-evaluate-time-range~) ::

  #+kindex: C-c C-y
  #+findex: org-evaluate-time-range
  #+cindex: evaluate time range
  Evaluate a time range by computing the difference between start and
  end.  With a prefix argument, insert result after the time range (in
  a table: into the following column).

*** The date/time prompt
:PROPERTIES:
:DESCRIPTION: How Org mode helps you enter dates and times.
:END:
#+cindex: date, reading in minibuffer
#+cindex: time, reading in minibuffer

#+vindex: org-read-date-prefer-future
When Org mode prompts for a date/time, the default is shown in default
date/time format, and the prompt therefore seems to ask for a specific
format.  But it in fact accepts date/time information in a variety of
formats.  Generally, the information should start at the beginning of
the string.  Org mode finds whatever information is in there and
derives anything you have not specified from the /default date and
time/.  The default is usually the current date and time, but when
modifying an existing timestamp, or when entering the second stamp of
a range, it is taken from the stamp in the buffer.  When filling in
information, Org mode assumes that most of the time you want to enter
a date in the future: if you omit the month/year and the given
day/month is /before/ today, it assumes that you mean a future
date[fn:21].  If the date has been automatically shifted into the
future, the time prompt shows this with =(=>F)=.

For example, let's assume that today is *June 13, 2006*.  Here is how
various inputs are interpreted, the items filled in by Org mode are in
*bold*.

| =3-2-5=        | \rArr{} 2003-02-05                              |
| =2/5/3=        | \rArr{} 2003-02-05                              |
| =14=           | \rArr{} *2006*-*06*-14                          |
| =12=           | \rArr{} *2006*-*07*-12                          |
| =2/5=          | \rArr{} *2007*-02-05                            |
| =Fri=          | \rArr{} nearest Friday (default date or later)  |
| =sep 15=       | \rArr{} *2006*-09-15                            |
| =feb 15=       | \rArr{} *2007*-02-15                            |
| =sep 12 9=     | \rArr{} 2009-09-12                              |
| =12:45=        | \rArr{} *2006*-*06*-*13* 12:45                  |
| =22 sept 0:34= | \rArr{} *2006*-09-22 0:34                       |
| =w4=           | \rArr{} ISO week for of the current year *2006* |
| =2012 w4 fri=  | \rArr{} Friday of ISO week 4 in 2012            |
| =2012-w04-5=   | \rArr{} Same as above                           |

Furthermore you can specify a relative date by giving, as the /first/
thing in the input: a plus/minus sign, a number and a letter---=h=,
=d=, =w=, =m= or =y=---to indicate a change in hours, days, weeks,
months, or years.  With =h= the date is relative to the current time,
with the other letters and a single plus or minus, the date is
relative to today at 00:00.  With a double plus or minus, it is
relative to the default date.  If instead of a single letter, you use
the abbreviation of day name, the date is the Nth such day, e.g.:

| =+0=    | \rArr{} today                       |
| =.=     | \rArr{} today                       |
| =+2h=   | \rArr{} two hours from now          |
| =+4d=   | \rArr{} four days from today        |
| =+4=    | \rArr{} same as +4d                 |
| =+2w=   | \rArr{} two weeks from today        |
| =++5=   | \rArr{} five days from default date |
| =+2tue= | \rArr{} second Tuesday from now     |

#+vindex: parse-time-months
#+vindex: parse-time-weekdays
The function understands English month and weekday abbreviations.  If
you want to use un-abbreviated names and/or other languages, configure
the variables ~parse-time-months~ and ~parse-time-weekdays~.

#+vindex: org-read-date-force-compatible-dates
Not all dates can be represented in a given Emacs implementation.  By
default Org mode forces dates into the compatibility range 1970--2037
which works on all Emacs implementations.  If you want to use dates
outside of this range, read the docstring of the variable
~org-read-date-force-compatible-dates~.

You can specify a time range by giving start and end times or by
giving a start time and a duration (in HH:MM format).  Use one or two
dash(es) as the separator in the former case and use =+= as the
separator in the latter case, e.g.:

| =11am-1:15pm=  | \rArr{} 11:00-13:15   |
| =11h-13h15=    | \rArr{} same as above |
| =11am--1:15pm= | \rArr{} same as above |
| =11am+2:15=    | \rArr{} same as above |

#+cindex: calendar, for selecting date
#+vindex: org-popup-calendar-for-date-prompt
Parallel to the minibuffer prompt, a calendar is popped up[fn:: If you
do not need/want the calendar, configure the variable
~org-popup-calendar-for-date-prompt~.].  When you exit the date
prompt, either by clicking on a date in the calendar, or by pressing
{{{kbd(RET)}}}, the date selected in the calendar is combined with the
information entered at the prompt.  You can control the calendar fully
from the minibuffer:

#+kindex: <
#+kindex: >
#+kindex: M-v
#+kindex: C-v
#+kindex: mouse-1
#+kindex: S-RIGHT
#+kindex: S-LEFT
#+kindex: S-DOWN
#+kindex: S-UP
#+kindex: M-S-RIGHT
#+kindex: M-S-LEFT
#+kindex: RET
#+kindex: .
#+kindex: C-.
#+attr_texinfo: :columns 0.25 0.55
| {{{kbd(RET)}}}       | Choose date at point in calendar.      |
| {{{kbd(mouse-1)}}}   | Select date by clicking on it.         |
| {{{kbd(S-RIGHT)}}}   | One day forward.                       |
| {{{kbd(S-LEFT)}}}    | One day backward.                      |
| {{{kbd(S-DOWN)}}}    | One week forward.                      |
| {{{kbd(S-UP)}}}      | One week backward.                     |
| {{{kbd(M-S-RIGHT)}}} | One month forward.                     |
| {{{kbd(M-S-LEFT)}}}  | One month backward.                    |
| {{{kbd(>)}}}         | Scroll calendar forward by one month.  |
| {{{kbd(<)}}}         | Scroll calendar backward by one month. |
| {{{kbd(M-v)}}}       | Scroll calendar forward by 3 months.   |
| {{{kbd(C-v)}}}       | Scroll calendar backward by 3 months.  |
| {{{kbd(C-.)}}}       | Select today's date[fn:22]             |

#+vindex: org-read-date-display-live
The actions of the date/time prompt may seem complex, but I assure you
they will grow on you, and you will start getting annoyed by pretty
much any other way of entering a date/time out there.  To help you
understand what is going on, the current interpretation of your input
is displayed live in the minibuffer[fn:: If you find this distracting,
turn off the display with ~org-read-date-display-live~.].

*** Custom time format
:PROPERTIES:
:DESCRIPTION: Making dates look different.
:END:
#+cindex: custom date/time format
#+cindex: time format, custom
#+cindex: date format, custom

#+vindex: org-display-custom-times
#+vindex: org-time-stamp-custom-formats
Org mode uses the standard ISO notation for dates and times as it is
defined in ISO 8601.  If you cannot get used to this and require
another representation of date and time to keep you happy, you can get
it by customizing the variables ~org-display-custom-times~ and
~org-time-stamp-custom-formats~.

- {{{kbd(C-c C-x C-t)}}} (~org-toggle-time-stamp-overlays~) ::

  #+kindex: C-c C-x C-t
  #+findex: org-toggle-time-stamp-overlays
  Toggle the display of custom formats for dates and times.

Org mode needs the default format for scanning, so the custom
date/time format does not /replace/ the default format.  Instead, it
is put /over/ the default format using text properties.  This has the
following consequences:

- You cannot place point onto a timestamp anymore, only before or
  after.

- The {{{kbd(S-UP)}}} and {{{kbd(S-DOWN)}}} keys can no longer be used
  to adjust each component of a timestamp.  If point is at the
  beginning of the stamp, {{{kbd(S-UP)}}} and {{{kbd(S-DOWN)}}} change
  the stamp by one day, just like {{{kbd(S-LEFT)}}}
  {{{kbd(S-RIGHT)}}}.  At the end of the stamp, change the time by one
  minute.

- If the timestamp contains a range of clock times or a repeater,
  these are not overlaid, but remain in the buffer as they were.

- When you delete a timestamp character-by-character, it only
  disappears from the buffer after /all/ (invisible) characters
  belonging to the ISO timestamp have been removed.

- If the custom timestamp format is longer than the default and you
  are using dates in tables, table alignment will be messed up.  If
  the custom format is shorter, things do work as expected.

** Deadlines and Scheduling
:PROPERTIES:
:DESCRIPTION: Planning your work.
:END:

A timestamp may be preceded by special keywords to facilitate
planning.  Both the timestamp and the keyword have to be positioned
immediately after the task they refer to.

- =DEADLINE= ::

  #+cindex: @samp{DEADLINE} marker
  Meaning: the task---most likely a TODO item, though not
  necessarily---is supposed to be finished on that date.

  #+vindex: org-deadline-warning-days
  On the deadline date, the task is listed in the agenda.  In
  addition, the agenda for /today/ carries a warning about the
  approaching or missed deadline, starting ~org-deadline-warning-days~
  before the due date, and continuing until the entry is marked as
  done.  An example:

  #+begin_example
  ,*** TODO write article about the Earth for the Guide
      DEADLINE: <2004-02-29 Sun>
      The editor in charge is [[bbdb:Ford Prefect]]
  #+end_example

  #+vindex: org-agenda-skip-deadline-prewarning-if-scheduled
  You can specify a different lead time for warnings for a specific
  deadlines using the following syntax.  Here is an example with
  a warning period of 5 days =DEADLINE: <2004-02-29 Sun -5d>=.  This
  warning is deactivated if the task gets scheduled and you set
  ~org-agenda-skip-deadline-prewarning-if-scheduled~ to ~t~.

- =SCHEDULED= ::

  #+cindex: @samp{SCHEDULED} marker
  Meaning: you are planning to start working on that task on the given
  date.

  #+vindex: org-agenda-skip-scheduled-if-done
  The headline is listed under the given date[fn:23].  In addition,
  a reminder that the scheduled date has passed is present in the
  compilation for /today/, until the entry is marked as done, i.e.,
  the task is automatically forwarded until completed.

  #+begin_example
  ,*** TODO Call Trillian for a date on New Years Eve.
      SCHEDULED: <2004-12-25 Sat>
  #+end_example

  #+vindex: org-scheduled-delay-days
  #+vindex: org-agenda-skip-scheduled-delay-if-deadline
  If you want to /delay/ the display of this task in the agenda, use
  =SCHEDULED: <2004-12-25 Sat -2d>=: the task is still scheduled on
  the 25th but will appear two days later.  In case the task contains
  a repeater, the delay is considered to affect all occurrences; if
  you want the delay to only affect the first scheduled occurrence of
  the task, use =--2d= instead.  See ~org-scheduled-delay-days~ and
  ~org-agenda-skip-scheduled-delay-if-deadline~ for details on how to
  control this globally or per agenda.

  #+attr_texinfo: :tag Important
  #+begin_quote
  Scheduling an item in Org mode should /not/ be understood in the
  same way that we understand /scheduling a meeting/.  Setting a date
  for a meeting is just a simple appointment, you should mark this
  entry with a simple plain timestamp, to get this item shown on the
  date where it applies.  This is a frequent misunderstanding by Org
  users.  In Org mode, /scheduling/ means setting a date when you want
  to start working on an action item.
  #+end_quote

You may use timestamps with repeaters in scheduling and deadline
entries.  Org mode issues early and late warnings based on the
assumption that the timestamp represents the /nearest instance/ of the
repeater.  However, the use of diary expression entries like

: <%%(diary-float t 42)>

#+texinfo: @noindent
in scheduling and deadline timestamps is limited.  Org mode does not
know enough about the internals of each function to issue early and
late warnings.  However, it shows the item on each day where the
expression entry matches.

*** Inserting deadlines or schedules
:PROPERTIES:
:DESCRIPTION: Planning items.
:ALT_TITLE: Inserting deadline/schedule
:END:

The following commands allow you to quickly insert a deadline or to
schedule an item:[fn:24]

- {{{kbd(C-c C-d)}}} (~org-deadline~) ::

  #+kindex: C-c C-d
  #+findex: org-deadline
  #+vindex: org-log-redeadline
  Insert =DEADLINE= keyword along with a stamp.  The insertion happens
  in the line directly following the headline.  Remove any =CLOSED=
  timestamp .  When called with a prefix argument, also remove any
  existing deadline from the entry.  Depending on the variable
  ~org-log-redeadline~, take a note when changing an existing
  deadline[fn:: Note the corresponding =STARTUP= options
  =logredeadline=, =lognoteredeadline=, and =nologredeadline=.].

- {{{kbd(C-c C-s)}}} (~org-schedule~) ::

  #+kindex: C-c C-s
  #+findex: org-schedule
  #+vindex: org-log-reschedule
  Insert =SCHEDULED= keyword along with a stamp.  The insertion
  happens in the line directly following the headline.  Remove any
  =CLOSED= timestamp.  When called with a prefix argument, also remove
  the scheduling date from the entry.  Depending on the variable
  ~org-log-reschedule~, take a note when changing an existing
  scheduling time[fn:: Note the corresponding =STARTUP= options
  =logreschedule=, =lognotereschedule=, and =nologreschedule=.].

- {{{kbd(C-c / d)}}} (~org-check-deadlines~) ::

  #+kindex: C-c / d
  #+findex: org-check-deadlines
  #+cindex: sparse tree, for deadlines
  #+vindex: org-deadline-warning-days
  Create a sparse tree with all deadlines that are either past-due, or
  which will become due within ~org-deadline-warning-days~.  With
  {{{kbd(C-u)}}} prefix, show all deadlines in the file.  With
  a numeric prefix, check that many days.  For example, {{{kbd(C-1 C-c
  / d)}}} shows all deadlines due tomorrow.

- {{{kbd(C-c / b)}}} (~org-check-before-date~) ::

  #+kindex: C-c / b
  #+findex: org-check-before-date
  Sparse tree for deadlines and scheduled items before a given date.

- {{{kbd(C-c / a)}}} (~org-check-after-date~) ::

  #+kindex: C-c / a
  #+findex: org-check-after-date
  Sparse tree for deadlines and scheduled items after a given date.

Note that ~org-schedule~ and ~org-deadline~ supports setting the date
by indicating a relative time e.g., =+1d= sets the date to the next
day after today, and =--1w= sets the date to the previous week before
any current timestamp.

*** Repeated tasks
:PROPERTIES:
:DESCRIPTION: Items that show up again and again.
:END:
#+cindex: tasks, repeated
#+cindex: repeated tasks

Some tasks need to be repeated again and again.  Org mode helps to
organize such tasks using a so-called repeater in a =DEADLINE=,
=SCHEDULED=, or plain timestamps[fn:25].  In the following example:

#+begin_example
,** TODO Pay the rent
   DEADLINE: <2005-10-01 Sat +1m>
#+end_example

#+texinfo: @noindent
the =+1m= is a repeater; the intended interpretation is that the task
has a deadline on =<2005-10-01>= and repeats itself every (one) month
starting from that time.  You can use yearly, monthly, weekly, daily
and hourly repeat cookies by using the =y=, =m=, =w=, =d= and =h=
letters.  If you need both a repeater and a special warning period in
a deadline entry, the repeater should come first and the warning
period last

: DEADLINE: <2005-10-01 Sat +1m -3d>

#+vindex: org-todo-repeat-to-state
Deadlines and scheduled items produce entries in the agenda when they
are over-due, so it is important to be able to mark such an entry as
done once you have done so.  When you mark a =DEADLINE= or a
=SCHEDULED= with the TODO keyword =DONE=, it no longer produces
entries in the agenda.  The problem with this is, however, is that
then also the /next/ instance of the repeated entry will not be
active.  Org mode deals with this in the following way: when you try
to mark such an entry as done, using {{{kbd(C-c C-t)}}}, it shifts the
base date of the repeating timestamp by the repeater interval, and
immediately sets the entry state back to TODO[fn:: In fact, the target
state is taken from, in this sequence, the =REPEAT_TO_STATE= property,
the variable ~org-todo-repeat-to-state~ if it is a string, the
previous TODO state if ~org-todo-repeat-to-state~ is ~t~, or the first
state of the TODO state sequence.].  In the example above, setting the
state to =DONE= would actually switch the date like this:

#+begin_example
,** TODO Pay the rent
   DEADLINE: <2005-11-01 Tue +1m>
#+end_example

To mark a task with a repeater as DONE, use {{{kbd(C-- 1 C-c C-t)}}},
i.e., ~org-todo~ with a numeric prefix argument of =-1=.

#+vindex: org-log-repeat
A timestamp[fn:26] is added under the deadline, to keep a record that
you actually acted on the previous instance of this deadline.

As a consequence of shifting the base date, this entry is no longer
visible in the agenda when checking past dates, but all future
instances will be visible.

With the =+1m= cookie, the date shift is always exactly one month.  So
if you have not paid the rent for three months, marking this entry
DONE still keeps it as an overdue deadline.  Depending on the task,
this may not be the best way to handle it.  For example, if you forgot
to call your father for 3 weeks, it does not make sense to call him
3 times in a single day to make up for it.  Finally, there are tasks,
like changing batteries, which should always repeat a certain time
/after/ the last time you did it.  For these tasks, Org mode has
special repeaters =++= and =.+=.  For example:

#+begin_example
,** TODO Call Father
   DEADLINE: <2008-02-10 Sun ++1w>
   Marking this DONE shifts the date by at least one week, but also
   by as many weeks as it takes to get this date into the future.
   However, it stays on a Sunday, even if you called and marked it
   done on Saturday.

,** TODO Empty kitchen trash
   DEADLINE: <2008-02-08 Fri 20:00 ++1d>
   Marking this DONE shifts the date by at least one day, and also
   by as many days as it takes to get the timestamp into the future.
   Since there is a time in the timestamp, the next deadline in the
   future will be on today's date if you complete the task before
   20:00.

,** TODO Check the batteries in the smoke detectors
   DEADLINE: <2005-11-01 Tue .+1m>
   Marking this DONE shifts the date to one month after today.

,** TODO Wash my hands
   DEADLINE: <2019-04-05 08:00 Fri .+1h>
   Marking this DONE shifts the date to exactly one hour from now.
#+end_example

#+vindex: org-agenda-skip-scheduled-if-deadline-is-shown
You may have both scheduling and deadline information for a specific
task.  If the repeater is set for the scheduling information only, you
probably want the repeater to be ignored after the deadline.  If so,
set the variable ~org-agenda-skip-scheduled-if-deadline-is-shown~ to
~repeated-after-deadline~.  However, any scheduling information
without a repeater is no longer relevant once the task is done, and
thus, removed upon repeating the task.  If you want both scheduling
and deadline information to repeat after the same interval, set the
same repeater for both timestamps.

An alternative to using a repeater is to create a number of copies of
a task subtree, with dates shifted in each copy.  The command
{{{kbd(C-c C-x c)}}} was created for this purpose; it is described in
[[*Structure Editing]].

** Clocking Work Time
:PROPERTIES:
:DESCRIPTION: Tracking how long you spend on a task.
:END:
#+cindex: clocking time
#+cindex: time clocking

Org mode allows you to clock the time you spend on specific tasks in
a project.  When you start working on an item, you can start the
clock.  When you stop working on that task, or when you mark the task
done, the clock is stopped and the corresponding time interval is
recorded.  It also computes the total time spent on each
subtree[fn:27] of a project.  And it remembers a history or tasks
recently clocked, so that you can jump quickly between a number of
tasks absorbing your time.

To save the clock history across Emacs sessions, use:

#+begin_src emacs-lisp
(setq org-clock-persist 'history)
(org-clock-persistence-insinuate)
#+end_src

#+vindex: org-clock-persist
When you clock into a new task after resuming Emacs, the incomplete
clock[fn:: To resume the clock under the assumption that you have
worked on this task while outside Emacs, use =(setq org-clock-persist
t)=.] is retrieved (see [[*Resolving idle time]]) and you are prompted
about what to do with it.

*** Clocking commands
:PROPERTIES:
:DESCRIPTION: Starting and stopping a clock.
:END:

#+attr_texinfo: :sep ,
- {{{kbd(C-c C-x C-i)}}} (~org-clock-in~) ::

  #+kindex: C-c C-x C-i
  #+findex: org-clock-in
  #+vindex: org-clock-into-drawer
  #+vindex: org-clock-continuously
  #+cindex: @samp{LOG_INTO_DRAWER}, property
  Start the clock on the current item (clock-in).  This inserts the
  =CLOCK= keyword together with a timestamp.  If this is not the first
  clocking of this item, the multiple =CLOCK= lines are wrapped into
  a =LOGBOOK= drawer (see also the variable ~org-clock-into-drawer~).
  You can also overrule the setting of this variable for a subtree by
  setting a =CLOCK_INTO_DRAWER= or =LOG_INTO_DRAWER= property.  When
  called with a {{{kbd(C-u)}}} prefix argument, select the task from
  a list of recently clocked tasks.  With two {{{kbd(C-u C-u)}}}
  prefixes, clock into the task at point and mark it as the default
  task; the default task is always be available with letter
  {{{kbd(d)}}} when selecting a clocking task.  With three {{{kbd(C-u
  C-u C-u)}}} prefixes, force continuous clocking by starting the
  clock when the last clock stopped.

  #+cindex: @samp{CLOCK_MODELINE_TOTAL}, property
  #+cindex: @samp{LAST_REPEAT}, property
  #+vindex: org-clock-mode-line-total
  #+vindex: org-clock-in-prepare-hook
  While the clock is running, Org shows the current clocking time in
  the mode line, along with the title of the task.  The clock time
  shown is all time ever clocked for this task and its children.  If
  the task has an effort estimate (see [[*Effort Estimates]]), the
  mode line displays the current clocking time against it[fn:: To add
  an effort estimate "on the fly", hook a function doing this to
  ~org-clock-in-prepare-hook~.].  If the task is a repeating one (see
  [[*Repeated tasks]]), show only the time since the last reset of the
  task[fn:: The last reset of the task is recorded by the
  =LAST_REPEAT= property.].  You can exercise more control over show
  time with the =CLOCK_MODELINE_TOTAL= property.  It may have the
  values =current= to show only the current clocking instance, =today=
  to show all time clocked on this tasks today---see also the variable
  ~org-extend-today-until~, ~all~ to include all time, or ~auto~ which
  is the default[fn:: See also the variable
  ~org-clock-mode-line-total~.].  Clicking with {{{kbd(mouse-1)}}}
  onto the mode line entry pops up a menu with clocking options.

- {{{kbd(C-c C-x C-o)}}} (~org-clock-out~) ::

  #+kindex: C-c C-x C-o
  #+findex: org-clock-out
  #+vindex: org-log-note-clock-out
  Stop the clock (clock-out).  This inserts another timestamp at the
  same location where the clock was last started.  It also directly
  computes the resulting time in inserts it after the time range as
  ==>HH:MM=.  See the variable ~org-log-note-clock-out~ for the
  possibility to record an additional note together with the clock-out
  timestamp[fn:: The corresponding in-buffer setting is: =#+STARTUP:
  lognoteclock-out=.].

- {{{kbd(C-c C-x C-x)}}} (~org-clock-in-last~) ::

  #+kindex: C-c C-x C-x
  #+findex: org-clock-in-last
  #+vindex: org-clock-continuously
  Re-clock the last clocked task.  With one {{{kbd(C-u)}}} prefix
  argument, select the task from the clock history.  With two
  {{{kbd(C-u)}}} prefixes, force continuous clocking by starting the
  clock when the last clock stopped.

- {{{kbd(C-c C-x C-e)}}} (~org-clock-modify-effort-estimate~) ::

  #+kindex: C-c C-x C-e
  #+findex: org-clock-modify-effort-estimate
  Update the effort estimate for the current clock task.

- {{{kbd(C-c C-c)}}} or {{{kbd(C-c C-y)}}} (~org-evaluate-time-range~) ::

  #+kindex: C-c C-c
  #+kindex: C-c C-y
  #+findex: org-evaluate-time-range
  Recompute the time interval after changing one of the timestamps.
  This is only necessary if you edit the timestamps directly.  If you
  change them with {{{kbd(S-<cursor>)}}} keys, the update is
  automatic.

- {{{kbd(C-S-UP)}}} (~org-clock-timestamps-up~), {{{kbd(C-S-DOWN)}}} (~org-clock-timestamps-down~) ::

  #+kindex: C-S-UP
  #+findex: org-clock-timestamps-up
  #+kindex: C-S-DOWN
  #+findex: org-clock-timestamps-down
  On CLOCK log lines, increase/decrease both timestamps so that the
  clock duration keeps the same value.

- {{{kbd(S-M-UP)}}} (~org-timestamp-up~), {{{kbd(S-M-DOWN)}}} (~org-timestamp-down~) ::

  #+kindex: S-M-UP
  #+findex: org-clock-timestamp-up
  #+kindex: S-M-DOWN
  #+findex: org-clock-timestamp-down
  On =CLOCK= log lines, increase/decrease the timestamp at point and
  the one of the previous, or the next, clock timestamp by the same
  duration.  For example, if you hit {{{kbd(S-M-UP)}}} to increase
  a clocked-out timestamp by five minutes, then the clocked-in
  timestamp of the next clock is increased by five minutes.

- {{{kbd(C-c C-t)}}} (~org-todo~) ::

  #+kindex: C-c C-t
  #+findex: org-todo
  Changing the TODO state of an item to DONE automatically stops the
  clock if it is running in this same item.

- {{{kbd(C-c C-x C-q)}}} (~org-clock-cancel~) ::

  #+kindex: C-c C-x C-q
  #+findex: org-clock-cancel
  Cancel the current clock.  This is useful if a clock was started by
  mistake, or if you ended up working on something else.

- {{{kbd(C-c C-x C-j)}}} (~org-clock-goto~) ::

  #+kindex: C-c C-x C-j
  #+findex: or-clock-goto
  Jump to the headline of the currently clocked in task.  With
  a {{{kbd(C-u)}}} prefix argument, select the target task from a list
  of recently clocked tasks.

- {{{kbd(C-c C-x C-d)}}} (~org-clock-display~) ::

  #+kindex: C-c C-x C-d
  #+findex: org-clock-display
  #+vindex: org-remove-highlights-with-change
  Display time summaries for each subtree in the current buffer.  This
  puts overlays at the end of each headline, showing the total time
  recorded under that heading, including the time of any subheadings.
  You can use visibility cycling to study the tree, but the overlays
  disappear when you change the buffer (see variable
  ~org-remove-highlights-with-change~) or press {{{kbd(C-c C-c)}}}.

The {{{kbd(l)}}} key may be used in the agenda (see [[*Weekly/daily
agenda]]) to show which tasks have been worked on or closed during
a day.

*Important:* note that both ~org-clock-out~ and ~org-clock-in-last~
can have a global keybinding and do not modify the window disposition.

*** The clock table
:PROPERTIES:
:DESCRIPTION: Detailed reports.
:END:
#+cindex: clocktable, dynamic block
#+cindex: report, of clocked time

Org mode can produce quite complex reports based on the time clocking
information.  Such a report is called a /clock table/, because it is
formatted as one or several Org tables.

#+attr_texinfo: :sep ,
- ~org-clock-report~ ::

  #+kindex: C-c C-x x
  #+findex: org-clock-report
  Insert or update a clock table.  When called with a prefix argument,
  jump to the first clock table in the current document and update it.
  The clock table includes archived trees.

  This command can be invoked by calling
  ~org-dynamic-block-insert-dblock~ ({{{kbd(C-c C-x x)}}}) and
  selecting "clocktable" (see [[*Dynamic Blocks]]).

- {{{kbd(C-c C-c)}}} or {{{kbd(C-c C-x C-u)}}} (~org-dblock-update~) ::

  #+kindex: C-c C-c
  #+kindex: C-c C-x C-u
  #+findex: org-dblock-update
  Update dynamic block at point.  Point needs to be in the =BEGIN=
  line of the dynamic block.

- {{{kbd(C-u C-c C-x C-u)}}} ::

  #+kindex: C-u C-c C-x C-u
  Update all dynamic blocks (see [[*Dynamic Blocks]]).  This is useful if
  you have several clock table blocks in a buffer.

- {{{kbd(S-LEFT)}}}, {{{kbd(S-RIGHT)}}} (~org-clocktable-try-shift~) ::

  #+kindex: S-LEFT
  #+kindex: S-RIGHT
  #+findex: org-clocktable-try-shift
  Shift the current =:block= interval and update the table.  Point
  needs to be in the =#+BEGIN: clocktable= line for this command.  If
  =:block= is =today=, it is shifted to =today-1=, etc.

Here is an example of the frame for a clock table as it is inserted
into the buffer by ~org-clock-report~:

#+cindex: @samp{BEGIN clocktable}
#+begin_example
,#+BEGIN: clocktable :maxlevel 2 :emphasize nil :scope file
,#+END:
#+end_example

#+vindex: org-clocktable-defaults
The =#+BEGIN= line contains options to define the scope, structure,
and formatting of the report.  Defaults for all these options can be
configured in the variable ~org-clocktable-defaults~.

First there are options that determine which clock entries are to
be selected:

- =:maxlevel= ::

  Maximum level depth to which times are listed in the table.  Clocks
  at deeper levels are summed into the upper level.

- =:scope= ::

  The scope to consider.  This can be any of the following:

  | =nil=                  | the current buffer or narrowed region                               |
  | =file=                 | the full current buffer                                             |
  | =subtree=              | the subtree where the clocktable is located                         |
  | =treeN=                | the surrounding level N tree, for example =tree3=                   |
  | =tree=                 | the surrounding level 1 tree                                        |
  | =agenda=               | all agenda files                                                    |
  | =("file" ...)=         | scan these files                                                    |
  | =FUNCTION=             | scan files returned by calling {{{var(FUNCTION)}}} with no argument |
  | =file-with-archives=   | current file and its archives                                       |
  | =agenda-with-archives= | all agenda files, including archives                                |

- =:block= ::

  The time block to consider.  This block is specified either
  absolutely, or relative to the current time and may be any of these
  formats:

  | =2007-12-31=                                                                                                  | New year eve 2007     |
  | =2007-12=                                                                                                     | December 2007         |
  | =2007-W50=                                                                                                    | ISO-week 50 in 2007   |
  | =2007-Q2=                                                                                                     | 2nd quarter in 2007   |
  | =2007=                                                                                                        | the year 2007         |
  | =today=, =yesterday=, =today-N=                                                                               | a relative day        |
  | =thisweek=, =lastweek=, =thisweek-N=                                                                          | a relative week       |
  | =thismonth=, =lastmonth=, =thismonth-N=                                                                       | a relative month      |
  | =thisyear=, =lastyear=, =thisyear-N=                                                                          | a relative year       |
  | =untilnow=[fn:: When using ~:step~, ~untilnow~ starts from the beginning of 2003, not the beginning of time.] | all clocked time ever |

  #+vindex: org-clock-display-default-range
  When this option is not set, Org falls back to the value in
  ~org-clock-display-default-range~, which defaults to the current
  year.

  Use {{{kbd(S-LEFT)}}} or {{{kbd(S-RIGHT)}}} to shift the time
  interval.

- =:tstart= ::

  A time string specifying when to start considering times.  Relative
  times like ="<-2w>"= can also be used.  See [[*Matching tags and
  properties]] for relative time syntax.

- =:tend= ::

  A time string specifying when to stop considering times.  Relative
  times like ="<now>"= can also be used.  See [[*Matching tags and
  properties]] for relative time syntax.

- =:wstart= ::

  The starting day of the week.  The default is 1 for Monday.

- =:mstart= ::

  The starting day of the month.  The default is 1 for the first.

- =:step= ::

  Set to =day=, =week=, =semimonth=, =month=, =quarter=, or =year= to split the
  table into chunks.  To use this, either =:block=, or =:tstart= and
  =:tend= are required.

- =:stepskip0= ::

  When non-~nil~, do not show steps that have zero time.

- =:fileskip0= ::

  When non-~nil~, do not show table sections from files which did not
  contribute.

- =:match= ::

  A tags match to select entries that should contribute.  See
  [[*Matching tags and properties]] for the match syntax.

#+findex: org-clocktable-write-default
Then there are options that determine the formatting of the table.
There options are interpreted by the function
~org-clocktable-write-default~, but you can specify your own function
using the =:formatter= parameter.

- =:emphasize= ::

  When non-~nil~, emphasize level one and level two items.

- =:lang= ::

  Language[fn:: Language terms can be set through the variable
  ~org-clock-clocktable-language-setup~.] to use for descriptive cells
  like "Task".

- =:link= ::

  Link the item headlines in the table to their origins.

- =:narrow= ::

  An integer to limit the width of the headline column in the Org
  table.  If you write it like =50!=, then the headline is also
  shortened in export.

- =:indent= ::

  Indent each headline field according to its level.

- =:filetitle= ::

  Show title in the file column if the file has a =#+title=.

- =:hidefiles= ::

  Hide the file column when multiple files are used to produce the
  table.

- =:tcolumns= ::

  Number of columns to be used for times.  If this is smaller than
  =:maxlevel=, lower levels are lumped into one column.

- =:level= ::

  Should a level number column be included?

- =:sort= ::

  A cons cell containing the column to sort and a sorting type.  E.g.,
  =:sort (1 . ?a)= sorts the first column alphabetically.

- =:compact= ::

  Abbreviation for =:level nil :indent t :narrow 40! :tcolumns 1=.
  All are overwritten except if there is an explicit =:narrow=.

- =:timestamp= ::

  A timestamp for the entry, when available.  Look for =SCHEDULED=,
  =DEADLINE=, =TIMESTAMP= and =TIMESTAMP_IA= special properties (see
  [[*Special Properties]]), in this order.

- =:tags= ::

  When this flag is non-~nil~, show the headline's tags.

- =:properties= ::

  List of properties shown in the table.  Each property gets its own
  column.

- =:inherit-props= ::

  When this flag is non-~nil~, the values for =:properties= are
  inherited.

- =:formula= ::

  Content of a =TBLFM= keyword to be added and evaluated.  As
  a special case, =:formula %= adds a column with % time.  If you do
  not specify a formula here, any existing formula below the clock
  table survives updates and is evaluated.

- =:formatter= ::

  A function to format clock data and insert it into the buffer.

To get a clock summary of the current level 1 tree, for the current
day, you could write:

#+begin_example
,#+BEGIN: clocktable :maxlevel 2 :block today :scope tree1 :link t
,#+END:
#+end_example

#+texinfo: @noindent
To use a specific time range you could write[fn:: Note that all
parameters must be specified in a single line---the line is broken
here only to fit it into the manual.]

#+begin_example
,#+BEGIN: clocktable :tstart "<2006-08-10 Thu 10:00>"
                    :tend "<2006-08-10 Thu 12:00>"
,#+END:
#+end_example

#+texinfo: @noindent
A range starting a week ago and ending right now could be written as

#+begin_example
,#+BEGIN: clocktable :tstart "<-1w>" :tend "<now>"
,#+END:
#+end_example

#+texinfo: @noindent
A summary of the current subtree with % times would be

#+begin_example
,#+BEGIN: clocktable :scope subtree :link t :formula %
,#+END:
#+end_example

#+texinfo: @noindent
A horizontally compact representation of everything clocked during
last week would be

#+begin_example
,#+BEGIN: clocktable :scope agenda :block lastweek :compact t
,#+END:
#+end_example

*** Resolving idle time and continuous clocking
:PROPERTIES:
:DESCRIPTION: Resolving time when you've been idle.
:ALT_TITLE: Resolving idle time
:END:

**** Resolving idle time
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: resolve idle time
#+cindex: idle, resolve, dangling

If you clock in on a work item, and then walk away from your
computer---perhaps to take a phone call---you often need to
"resolve" the time you were away by either subtracting it from the
current clock, or applying it to another one.

#+vindex: org-clock-idle-time
#+vindex: org-clock-x11idle-program-name
By customizing the variable ~org-clock-idle-time~ to some integer,
such as 10 or 15, Emacs can alert you when you get back to your
computer after being idle for that many minutes[fn:28], and ask what
you want to do with the idle time.  There will be a question waiting
for you when you get back, indicating how much idle time has passed
constantly updated with the current amount, as well as a set of
choices to correct the discrepancy:

- {{{kbd(k)}}} ::

  #+kindex: k
  To keep some or all of the minutes and stay clocked in, press
  {{{kbd(k)}}}.  Org asks how many of the minutes to keep.  Press
  {{{kbd(RET)}}} to keep them all, effectively changing nothing, or
  enter a number to keep that many minutes.

- {{{kbd(K)}}} ::

  #+kindex: K
  If you use the shift key and press {{{kbd(K)}}}, it keeps however
  many minutes you request and then immediately clock out of that
  task.  If you keep all of the minutes, this is the same as just
  clocking out of the current task.

- {{{kbd(s)}}} ::

  #+kindex: s
  To keep none of the minutes, use {{{kbd(s)}}} to subtract all the
  away time from the clock, and then check back in from the moment you
  returned.

- {{{kbd(S)}}} ::

  #+kindex: S
  To keep none of the minutes and just clock out at the start of the
  away time, use the shift key and press {{{kbd(S)}}}.  Remember that
  using shift always leave you clocked out, no matter which option you
  choose.

- {{{kbd(C)}}} ::

  #+kindex: C
  To cancel the clock altogether, use {{{kbd(C)}}}.  Note that if
  instead of canceling you subtract the away time, and the resulting
  clock amount is less than a minute, the clock is still canceled
  rather than cluttering up the log with an empty entry.

What if you subtracted those away minutes from the current clock, and
now want to apply them to a new clock?  Simply clock in to any task
immediately after the subtraction.  Org will notice that you have
subtracted time "on the books", so to speak, and will ask if you want
to apply those minutes to the next task you clock in on.

There is one other instance when this clock resolution magic occurs.
Say you were clocked in and hacking away, and suddenly your cat chased
a mouse who scared a hamster that crashed into your UPS's power
button!  You suddenly lose all your buffers, but thanks to auto-save
you still have your recent Org mode changes, including your last clock
in.

If you restart Emacs and clock into any task, Org will notice that you
have a dangling clock which was never clocked out from your last
session.  Using that clock's starting time as the beginning of the
unaccounted-for period, Org will ask how you want to resolve that
time.  The logic and behavior is identical to dealing with away time
due to idleness; it is just happening due to a recovery event rather
than a set amount of idle time.

You can also check all the files visited by your Org agenda for
dangling clocks at any time using {{{kbd(M-x org-resolve-clocks
RET)}}} (or {{{kbd(C-c C-x C-z)}}}).

**** Continuous clocking
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: continuous clocking

#+vindex: org-clock-continuously
You may want to start clocking from the time when you clocked out the
previous task.  To enable this systematically, set
~org-clock-continuously~ to non-~nil~.  Each time you clock in, Org
retrieves the clock-out time of the last clocked entry for this
session, and start the new clock from there.

If you only want this from time to time, use three universal prefix
arguments with ~org-clock-in~ and two {{{kbd(C-u C-u)}}} with
~org-clock-in-last~.

**** Clocking out automatically after some idle time
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: auto clocking out after idle time

#+vindex: org-clock-auto-clockout-timer
When you often forget to clock out before being idle and you don't
want to manually set the clocking time to take into account, you can
set ~org-clock-auto-clockout-timer~ to a number of seconds and add
=(org-clock-auto-clockout-insinuate)= to your =.emacs= file.

When the clock is running and Emacs is idle for more than this number
of seconds, the clock will be clocked out automatically.

Use =M-x org-clock-toggle-auto-clockout RET= to temporarily turn this
on or off.

** Effort Estimates
:PROPERTIES:
:DESCRIPTION: Planning work effort in advance.
:END:
#+cindex: effort estimates
#+cindex: @samp{EFFORT}, property
#+vindex: org-effort-property

If you want to plan your work in a very detailed way, or if you need
to produce offers with quotations of the estimated work effort, you
may want to assign effort estimates to entries.  If you are also
clocking your work, you may later want to compare the planned effort
with the actual working time, a great way to improve planning
estimates.

Effort estimates are stored in a special property =EFFORT=.  Multiple
formats are supported, such as =3:12=, =1:23:45=, or =1d3h5min=; see
the file =org-duration.el= for more detailed information about the
format.

You can set the effort for an entry with the following commands:

- {{{kbd(C-c C-x e)}}}  (~org-set-effort~) ::

  #+kindex: C-c C-x e
  #+findex: org-set-effort
  Set the effort estimate for the current entry.  With a prefix
  argument, set it to the next allowed value---see below.  This
  command is also accessible from the agenda with the {{{kbd(e)}}}
  key.

- {{{kbd(C-c C-x C-e)}}} (~org-clock-modify-effort-estimate~) ::

  #+kindex: C-c C-x C-e
  #+findex: org-clock-modify-effort-estimate
  Modify the effort estimate of the item currently being clocked.

Clearly the best way to work with effort estimates is through column
view (see [[*Column View]]).  You should start by setting up discrete
values for effort estimates, and a =COLUMNS= format that displays
these values together with clock sums---if you want to clock your
time.  For a specific buffer you can use:

#+begin_example
,#+PROPERTY: Effort_ALL 0 0:10 0:30 1:00 2:00 3:00 4:00 5:00 6:00 7:00
,#+COLUMNS: %40ITEM(Task) %17Effort(Estimated Effort){:} %CLOCKSUM
#+end_example

#+texinfo: @noindent
#+vindex: org-global-properties
#+vindex: org-columns-default-format
or, even better, you can set up these values globally by customizing
the variables ~org-global-properties~ and
~org-columns-default-format~.  In particular if you want to use this
setup also in the agenda, a global setup may be advised.

The way to assign estimates to individual items is then to switch to
column mode, and to use {{{kbd(S-RIGHT)}}} and {{{kbd(S-LEFT)}}} to
change the value.  The values you enter are immediately summed up in
the hierarchy.  In the column next to it, any clocked time is
displayed.

#+vindex: org-agenda-columns-add-appointments-to-effort-sum
If you switch to column view in the daily/weekly agenda, the effort
column summarizes the estimated work effort for each day[fn:: Please
note the pitfalls of summing hierarchical data in a flat list (see
[[*Using Column View in the Agenda]]).], and you can use this to find
space in your schedule.  To get an overview of the entire part of the
day that is committed, you can set the option
~org-agenda-columns-add-appointments-to-effort-sum~.  The appointments
on a day that take place over a specified time interval are then also
added to the load estimate of the day.

Effort estimates can be used in secondary agenda filtering that is
triggered with the {{{kbd(/)}}} key in the agenda (see [[*Commands in
the Agenda Buffer]]).  If you have these estimates defined consistently,
two or three key presses narrow down the list to stuff that fits into
an available time slot.

** Taking Notes with a Relative Timer
:PROPERTIES:
:DESCRIPTION: Notes with a running timer.
:ALT_TITLE: Timers
:END:
#+cindex: relative timer
#+cindex: countdown timer

Org provides two types of timers.  There is a relative timer that
counts up, which can be useful when taking notes during, for example,
a meeting or a video viewing.  There is also a countdown timer.

The relative and countdown are started with separate commands.

- {{{kbd(C-c C-x 0)}}} (~org-timer-start~) ::

  #+kindex: C-c C-x 0
  #+findex: org-timer-start
  Start or reset the relative timer.  By default, the timer is set
  to 0.  When called with a {{{kbd(C-u)}}} prefix, prompt the user for
  a starting offset.  The prompt will default to a timer string at
  point (if any), providing a convenient way to restart taking notes
  after a break in the process.  When called with a double prefix
  argument {{{kbd(C-u C-u)}}}, change all timer strings in the active
  region by a certain amount.  This can be used to fix timer strings
  if the timer was not started at exactly the right moment.

- {{{kbd(C-c C-x ;)}}} (~org-timer-set-timer~) ::

  #+kindex: C-c C-x ;
  #+findex: org-timer-set-timer
  #+vindex: org-timer-default-timer
  Start a countdown timer.  The user is prompted for a duration.
  ~org-timer-default-timer~ sets the default countdown value.  Giving
  a numeric prefix argument overrides this default value.  This
  command is available as {{{kbd(;)}}} in agenda buffers.

Once started, relative and countdown timers are controlled with the
same commands.

- {{{kbd(C-c C-x .)}}} (~org-timer~) ::

  #+kindex: C-c C-x .
  #+findex: org-timer
  Insert a relative time into the buffer.  The first time you use
  this, the timer starts.  Using a prefix argument restarts it.

- {{{kbd(C-c C-x -)}}} (~org-timer-item~) ::

  #+kindex: C-c C-x -
  #+findex: org-timer-item
  Insert a description list item with the current relative time.  With
  a prefix argument, first reset the timer to 0.

- {{{kbd(M-RET)}}} (~org-insert-heading~) ::

  #+kindex: M-RET
  #+findex: org-insert-heading
  Once the timer list is started, you can also use {{{kbd(M-RET)}}} to
  insert new timer items.

- {{{kbd(C-c C-x \,)}}} (~org-timer-pause-or-continue~) ::

  #+kindex: C-c C-x ,
  #+findex: org-timer-pause-or-continue
  Pause the timer, or continue it if it is already paused.

- {{{kbd(C-c C-x _)}}} (~org-timer-stop~) ::

  #+kindex: C-c C-x _
  #+findex: org-timer-stop
  Stop the timer.  After this, you can only start a new timer, not
  continue the old one.  This command also removes the timer from the
  mode line.

* Refiling and Archiving
:PROPERTIES:
:DESCRIPTION: Moving and copying information with ease.
:END:
#+cindex: refiling notes
#+cindex: copying notes
#+cindex: archiving

Once information is in the system, it may need to be moved around.
Org provides Refile, Copy and Archive commands for this.  Refile and
Copy helps with moving and copying outlines.  Archiving helps to keep
the system compact and fast.

** Refile and Copy
:PROPERTIES:
:DESCRIPTION: Moving/copying a tree from one place to another.
:END:
#+cindex: refiling notes
#+cindex: copying notes

When reviewing the captured data, you may want to refile or to copy
some of the entries into a different list, for example into a project.
Cutting, finding the right location, and then pasting the note is
cumbersome.  To simplify this process, you can use the following
special command:

- {{{kbd(C-c C-w)}}} (~org-refile~) ::

  #+kindex: C-c C-w
  #+findex: org-refile
  #+vindex: org-reverse-note-order
  #+vindex: org-refile-targets
  #+vindex: org-refile-use-outline-path
  #+vindex: org-outline-path-complete-in-steps
  #+vindex: org-refile-allow-creating-parent-nodes
  #+vindex: org-log-refile
  Refile the entry or region at point.  This command offers possible
  locations for refiling the entry and lets you select one with
  completion.  The item (or all items in the region) is filed below
  the target heading as a subitem.  Depending on
  ~org-reverse-note-order~, it is either the first or last subitem.

  By default, all level 1 headlines in the current buffer are
  considered to be targets, but you can have more complex definitions
  across a number of files.  See the variable ~org-refile-targets~ for
  details.  If you would like to select a location via a
  file-path-like completion along the outline path, see the variables
  ~org-refile-use-outline-path~ and
  ~org-outline-path-complete-in-steps~.  If you would like to be able
  to create new nodes as new parents for refiling on the fly, check
  the variable ~org-refile-allow-creating-parent-nodes~.  When the
  variable ~org-log-refile~[fn:: Note the corresponding =STARTUP=
  options =logrefile=, =lognoterefile=, and =nologrefile=.] is set, a
  timestamp or a note is recorded whenever an entry is refiled.

- {{{kbd(C-u C-c C-w)}}} ::

  #+kindex: C-u C-c C-w
  Use the refile interface to jump to a heading.

- {{{kbd(C-u C-u C-c C-w)}}} (~org-refile-goto-last-stored~) ::

  #+kindex: C-u C-u C-c C-w
  #+findex: org-refile-goto-last-stored
  Jump to the location where ~org-refile~ last moved a tree to.

- {{{kbd(C-2 C-c C-w)}}} ::

  #+kindex: C-2 C-c C-w
  Refile as the child of the item currently being clocked.

- {{{kbd(C-3 C-c C-w)}}} ::

  #+kindex: C-3 C-c C-w
  #+vindex: org-refile-keep
  Refile and keep the entry in place.  Also see ~org-refile-keep~ to
  make this the default behavior, and beware that this may result in
  duplicated =ID= properties.

- {{{kbd(C-0 C-c C-w)}}} or {{{kbd(C-u C-u C-u C-c C-w)}}} (~org-refile-cache-clear~) ::

  #+kindex: C-u C-u C-u C-c C-w
  #+kindex: C-0 C-c C-w
  #+findex: org-refile-cache-clear
  #+vindex: org-refile-use-cache
  Clear the target cache.  Caching of refile targets can be turned on
  by setting ~org-refile-use-cache~.  To make the command see new
  possible targets, you have to clear the cache with this command.

- {{{kbd(C-c M-w)}}} (~org-refile-copy~) ::

  #+kindex: C-c M-w
  #+findex: org-refile-copy
  Copying works like refiling, except that the original note is not
  deleted.

- {{{kbd(C-c C-M-w)}}} (~org-refile-reverse~) ::

  #+kindex: C-c C-M-w
  #+findex: org-refile-reverse
  Works like refiling, except that it temporarily toggles how the
  value of ~org-reverse-note-order~ applies to the current buffer.  So
  if ~org-refile~ would append the entry as the last entry under the
  target header, ~org-refile-reverse~ will prepend it as the first
  entry, and vice-versa.

** Archiving
:PROPERTIES:
:DESCRIPTION: What to do with finished products.
:END:
#+cindex: archiving

When a project represented by a (sub)tree is finished, you may want to
move the tree out of the way and to stop it from contributing to the
agenda.  Archiving is important to keep your working files compact and
global searches like the construction of agenda views fast.

- {{{kbd(C-c C-x C-a)}}} (~org-archive-subtree-default~) ::

  #+kindex: C-c C-x C-a
  #+findex: org-archive-subtree-default
  #+vindex: org-archive-default-command
  Archive the current entry using the command specified in the
  variable ~org-archive-default-command~.

*** Moving a tree to an archive file
:PROPERTIES:
:DESCRIPTION: Moving a tree to an archive file.
:ALT_TITLE: Moving subtrees
:END:
#+cindex: external archiving

The most common archiving action is to move a project tree to another
file, the archive file.

- {{{kbd(C-c C-x C-s)}}} or short {{{kbd(C-c $)}}} (~org-archive-subtree~) ::

  #+kindex: C-c C-x C-s
  #+kindex: C-c $
  #+findex: org-archive-subtree
  #+vindex: org-archive-location
  Archive the subtree starting at point position to the location given
  by ~org-archive-location~.

- {{{kbd(C-u C-c C-x C-s)}}} ::

  #+kindex: C-u C-c C-x C-s
  Check if any direct children of the current headline could be moved
  to the archive.  To do this, check each subtree for open TODO
  entries.  If none is found, the command offers to move it to the
  archive location.  If point is /not/ on a headline when this command
  is invoked, check level 1 trees.

- {{{kbd(C-u C-u C-c C-x C-s)}}} ::

  #+kindex: C-u C-u C-c C-x C-s
  As above, but check subtree for timestamps instead of TODO entries.
  The command offers to archive the subtree if it /does/ contain
  a timestamp, and that timestamp is in the past.

#+cindex: archive locations
The default archive location is a file in the same directory as the
current file, with the name derived by appending =_archive= to the
current file name.  You can also choose what heading to file archived
items under, with the possibility to add them to a datetree in a file.
For information and examples on how to specify the file and the
heading, see the documentation string of the variable
~org-archive-location~.

There is also an in-buffer option for setting this variable, for
example:

#+cindex: @samp{ARCHIVE}, keyword
: #+ARCHIVE: %s_done::

#+cindex: ARCHIVE, property
If you would like to have a special archive location for a single
entry or a (sub)tree, give the entry an =ARCHIVE= property with the
location as the value (see [[*Properties and Columns]]).

#+vindex: org-archive-save-context-info
When a subtree is moved, it receives a number of special properties
that record context information like the file from where the entry
came, its outline path the archiving time etc.  Configure the variable
~org-archive-save-context-info~ to adjust the amount of information
added.

#+vindex: org-archive-subtree-save-file-p
When ~org-archive-subtree-save-file-p~ is non-~nil~, save the target
archive buffer.

*** Internal archiving
:PROPERTIES:
:DESCRIPTION: Switch off a tree but keep it in the file.
:END:

#+cindex: @samp{ARCHIVE}, tag
If you want to just switch off---for agenda views---certain subtrees
without moving them to a different file, you can use the =ARCHIVE=
tag.

A headline that is marked with the =ARCHIVE= tag (see [[*Tags]]) stays at
its location in the outline tree, but behaves in the following way:

-
  #+vindex: org-cycle-open-archived-trees
  It does not open when you attempt to do so with a visibility cycling
  command (see [[*Visibility Cycling]]).  You can force cycling archived
  subtrees with {{{kbd(C-c C-TAB)}}}, or by setting the option
  ~org-cycle-open-archived-trees~.  Also normal outline commands, like
  ~org-show-all~, open archived subtrees.

-
  #+vindex: org-sparse-tree-open-archived-trees
  During sparse tree construction (see [[*Sparse Trees]]), matches in
  archived subtrees are not exposed, unless you configure the option
  ~org-sparse-tree-open-archived-trees~.

-
  #+vindex: org-agenda-skip-archived-trees
  During agenda view construction (see [[*Agenda Views]]), the content of
  archived trees is ignored unless you configure the option
  ~org-agenda-skip-archived-trees~, in which case these trees are
  always included.  In the agenda you can press {{{kbd(v a)}}} to get
  archives temporarily included.

-
  #+vindex: org-export-with-archived-trees
  Archived trees are not exported (see [[*Exporting]]), only the headline
  is.  Configure the details using the variable
  ~org-export-with-archived-trees~.

-
  #+vindex: org-columns-skip-archived-trees
  Archived trees are excluded from column view unless the variable
  ~org-columns-skip-archived-trees~ is configured to ~nil~.

The following commands help manage the =ARCHIVE= tag:

- {{{kbd(C-c C-x a)}}} (~org-toggle-archive-tag~) ::

  #+kindex: C-c C-x a
  #+findex: org-toggle-archive-tag
  Toggle the archive tag for the current headline.  When the tag is
  set, the headline changes to a shadowed face, and the subtree below
  it is hidden.

- {{{kbd(C-u C-c C-x a)}}} ::

  #+kindex: C-u C-c C-x a
  Check if any direct children of the current headline should be
  archived.  To do this, check each subtree for open TODO entries.  If
  none is found, the command offers to set the =ARCHIVE= tag for the
  child.  If point is /not/ on a headline when this command is
  invoked, check the level 1 trees.

- {{{kbd(C-c C-TAB)}}} (~org-cycle-force-archived~) ::

  #+kindex: C-c C-TAB
  Cycle a tree even if it is tagged with =ARCHIVE=.

- {{{kbd(C-c C-x A)}}} (~org-archive-to-archive-sibling~) ::

  #+kindex: C-c C-x A
  #+findex: org-archive-to-archive-sibling
  Move the current entry to the /Archive Sibling/.  This is a sibling
  of the entry with the heading =Archive= and the archive tag.  The
  entry becomes a child of that sibling and in this way retains a lot
  of its original context, including inherited tags and approximate
  position in the outline.

* Capture and Attachments
:PROPERTIES:
:DESCRIPTION: Dealing with external data.
:END:
#+cindex: capture
#+cindex: attachments
#+cindex: RSS feeds
#+cindex: Atom feeds
#+cindex: protocols, for external access

An important part of any organization system is the ability to quickly
capture new ideas and tasks, and to associate reference material with
them.  Org does this using a process called /capture/.  It also can
store files related to a task (/attachments/) in a special directory.
Finally, it can parse RSS feeds for information.  To learn how to let
external programs (for example a web browser) trigger Org to capture
material, see [[*Protocols for External Access]].

** Capture
:PROPERTIES:
:DESCRIPTION: Capturing new stuff.
:END:
#+cindex: capture

Capture lets you quickly store notes with little interruption of your
work flow.  Org's method for capturing new items is heavily inspired
by John Wiegley's excellent Remember package.

*** Setting up capture
:PROPERTIES:
:DESCRIPTION: Where notes will be stored.
:END:

The following customization sets a default target file for notes.

#+vindex: org-default-notes-file
#+begin_src emacs-lisp
(setq org-default-notes-file (concat org-directory "/notes.org"))
#+end_src

You may also define a global key for capturing new material (see
[[*Activation]]).

*** Using capture
:PROPERTIES:
:DESCRIPTION: Commands to invoke and terminate capture.
:END:

- {{{kbd(M-x org-capture)}}} (~org-capture~) ::

  #+findex: org-capture
  Display the capture templates menu.  If you have templates defined
  (see [[*Capture templates]]), it offers these templates for selection or
  use a new Org outline node as the default template.  It inserts the
  template into the target file and switch to an indirect buffer
  narrowed to this new node.  You may then insert the information you
  want.

- {{{kbd(C-c C-c)}}} (~org-capture-finalize~) ::

  #+kindex: C-c C-c @r{(Capture buffer)}
  #+findex: org-capture-finalize
  Once you have finished entering information into the capture buffer,
  {{{kbd(C-c C-c)}}} returns you to the window configuration before
  the capture process, so that you can resume your work without
  further distraction.  When called with a prefix argument, finalize
  and then jump to the captured item.

- {{{kbd(C-c C-w)}}} (~org-capture-refile~) ::

  #+kindex: C-c C-w @r{(Capture buffer)}
  #+findex: org-capture-refile
  Finalize the capture process by refiling the note to a different
  place (see [[*Refile and Copy]]).  Please realize that this is a normal
  refiling command that will be executed---so point position at the
  moment you run this command is important.  If you have inserted
  a tree with a parent and children, first move point back to the
  parent.  Any prefix argument given to this command is passed on to
  the ~org-refile~ command.

- {{{kbd(C-c C-k)}}} (~org-capture-kill~) ::

  #+kindex: C-c C-k @r{(Capture buffer)}
  #+findex: org-capture-kill
  Abort the capture process and return to the previous state.

#+kindex: k c @r{(Agenda)}
You can also call ~org-capture~ in a special way from the agenda,
using the {{{kbd(k c)}}} key combination.  With this access, any
timestamps inserted by the selected capture template defaults to the
date at point in the agenda, rather than to the current date.

To find the locations of the last stored capture, use ~org-capture~
with prefix commands:

- {{{kbd(C-u M-x org-capture)}}} ::

  Visit the target location of a capture template.  You get to select
  the template in the usual way.

- {{{kbd(C-u C-u M-x org-capture)}}} ::

  Visit the last stored capture item in its buffer.

#+vindex: org-capture-bookmark
#+vindex: org-capture-last-stored
You can also jump to the bookmark ~org-capture-last-stored~, which is
automatically created unless you set ~org-capture-bookmark~ to ~nil~.

To insert the capture at point in an Org buffer, call ~org-capture~
with a {{{kbd(C-0)}}} prefix argument.

*** Capture templates
:PROPERTIES:
:DESCRIPTION: Define the outline of different note types.
:END:
#+cindex: templates, for Capture

You can use templates for different types of capture items, and for
different target locations.  The easiest way to create such templates
is through the customize interface.

- {{{kbd(C)}}} ::

  #+kindex: C @r{(Capture menu}
  #+vindex: org-capture-templates
  Customize the variable ~org-capture-templates~.

Before we give the formal description of template definitions, let's
look at an example.  Say you would like to use one template to create
general TODO entries, and you want to put these entries under the
heading =Tasks= in your file =~/org/gtd.org=.  Also, a date tree in
the file =journal.org= should capture journal entries.  A possible
configuration would look like:

#+begin_src emacs-lisp
(setq org-capture-templates
      '(("t" "Todo" entry (file+headline "~/org/gtd.org" "Tasks")
         "* TODO %?\n  %i\n  %a")
        ("j" "Journal" entry (file+datetree "~/org/journal.org")
         "* %?\nEntered on %U\n  %i\n  %a")))
#+end_src

If you then press {{{kbd(t)}}} from the capture menu, Org will prepare
the template for you like this:

#+begin_example
,* TODO
  [[file:LINK TO WHERE YOU INITIATED CAPTURE]]
#+end_example

#+texinfo: @noindent
During expansion of the template, =%a= has been replaced by a link to
the location from where you called the capture command.  This can be
extremely useful for deriving tasks from emails, for example.  You
fill in the task definition, press {{{kbd(C-c C-c)}}} and Org returns
you to the same place where you started the capture process.

To define special keys to capture to a particular template without
going through the interactive template selection, you can create your
key binding like this:

#+begin_src emacs-lisp
(define-key global-map (kbd "C-c x")
  (lambda () (interactive) (org-capture nil "x")))
#+end_src

**** Template elements
:PROPERTIES:
:DESCRIPTION: What is needed for a complete template entry.
:END:

Now lets look at the elements of a template definition.  Each entry in
~org-capture-templates~ is a list with the following items:

- keys ::

  The keys that selects the template, as a string, characters only,
  for example ="a"=, for a template to be selected with a single key,
  or ="bt"= for selection with two keys.  When using several keys,
  keys using the same prefix key must be sequential in the list and
  preceded by a 2-element entry explaining the prefix key, for
  example:

  #+begin_src emacs-lisp
  ("b" "Templates for marking stuff to buy")
  #+end_src

  If you do not define a template for the {{{kbd(C)}}} key, this key
  opens the Customize buffer for this complex variable.

- description ::

  A short string describing the template, shown during selection.

- type ::

  The type of entry, a symbol.  Valid values are:

  - ~entry~ ::

    An Org mode node, with a headline.  Will be filed as the child of
    the target entry or as a top-level entry.  The target file should
    be an Org file.

  - ~item~ ::

    A plain list item, placed in the first plain list at the target
    location.  Again the target file should be an Org file.

  - ~checkitem~ ::

    A checkbox item.  This only differs from the plain list item by
    the default template.

  - ~table-line~ ::

    A new line in the first table at the target location.  Where
    exactly the line will be inserted depends on the properties
    ~:prepend~ and ~:table-line-pos~ (see below).

  - ~plain~ ::

    Text to be inserted as it is.

- target ::

  #+vindex: org-default-notes-file
  #+vindex: org-directory
  #+cindex: date tree
  Specification of where the captured item should be placed.  In Org
  files, targets usually define a node.  Entries will become children
  of this node.  Other types will be added to the table or list in the
  body of this node.  Most target specifications contain a file name.
  If that file name is the empty string, it defaults to
  ~org-default-notes-file~.  A file can also be given as a variable or
  as a function called with no argument.  When an absolute path is not
  specified for a target, it is taken as relative to ~org-directory~.

  Valid values are:

  - =(file "path/to/file")= ::

    Text will be placed at the beginning or end of that file.

  - =(id "id of existing org entry")= ::

    Filing as child of this entry, or in the body of the entry.

  - =(file+headline "filename" "node headline")= ::

    Fast configuration if the target heading is unique in the file.

  - =(file+olp "filename" "Level 1 heading" "Level 2" ...)= ::

    For non-unique headings, the full path is safer.

  - =(file+regexp "filename" "regexp to find location")= ::

    Use a regular expression to position point.

  - =(file+olp+datetree "filename" [ "Level 1 heading" ...])= ::

    This target[fn:29] creates a heading in a date tree[fn:30] for
    today's date.  If the optional outline path is given, the tree
    will be built under the node it is pointing to, instead of at top
    level.  Check out the ~:time-prompt~ and ~:tree-type~ properties
    below for additional options.

  - =(file+function "filename" function-finding-location)= ::

    A function to find the right location in the file.

  - =(clock)= ::

    File to the entry that is currently being clocked.

  - =(function function-finding-location)= ::

    Most general way: write your own function which both visits the
    file and moves point to the right location.

- template ::

  The template for creating the capture item.  If you leave this
  empty, an appropriate default template will be used.  Otherwise this
  is a string with escape codes, which will be replaced depending on
  time and context of the capture call.  You may also get this
  template string from a file[fn:: When the file name is not absolute,
  Org assumes it is relative to ~org-directory~.], or dynamically,
  from a function using either syntax:

  : (file "/path/to/template-file")
  : (function FUNCTION-RETURNING-THE-TEMPLATE)

- properties ::

  The rest of the entry is a property list of additional options.
  Recognized properties are:

  - ~:prepend~ ::

    Normally new captured information will be appended at the target
    location (last child, last table line, last list item, ...).
    Setting this property changes that.

  - ~:immediate-finish~ ::

    When set, do not offer to edit the information, just file it away
    immediately.  This makes sense if the template only needs
    information that can be added automatically.

  - ~:jump-to-captured~ ::

    When set, jump to the captured entry when finished.

  - ~:empty-lines~ ::

    Set this to the number of lines to insert before and after the new
    item.  Default 0, and the only other common value is 1.

  - ~:empty-lines-after~ ::

    Set this to the number of lines that should be inserted after the
    new item.  Overrides ~:empty-lines~ for the number of lines
    inserted after.

  - ~:empty-lines-before~ ::

    Set this to the number of lines that should be inserted before the
    new item.  Overrides ~:empty-lines~ for the number lines inserted
    before.

  - ~:clock-in~ ::

    Start the clock in this item.

  - ~:clock-keep~ ::

    Keep the clock running when filing the captured entry.

  - ~:clock-resume~ ::

    If starting the capture interrupted a clock, restart that clock
    when finished with the capture.  Note that ~:clock-keep~ has
    precedence over ~:clock-resume~.  When setting both to non-~nil~,
    the current clock will run and the previous one will not be
    resumed.

  - ~:time-prompt~ ::

    Prompt for a date/time to be used for date/week trees and when
    filling the template.  Without this property, capture uses the
    current date and time.  Even if this property has not been set,
    you can force the same behavior by calling ~org-capture~ with
    a {{{kbd(C-1)}}} prefix argument.

  - ~:tree-type~ ::

    Use ~week~ to make a week tree instead of the month-day tree,
    i.e., place the headings for each day under a heading with the
    current ISO week.  Use ~month~ to group entries by month
    only.  Default is to group entries by day.

  - ~:unnarrowed~ ::

    Do not narrow the target buffer, simply show the full buffer.
    Default is to narrow it so that you only see the new material.

  - ~:table-line-pos~ ::

    Specification of the location in the table where the new line
    should be inserted.  It should be a string like =II-3= meaning
    that the new line should become the third line before the second
    horizontal separator line.

  - ~:kill-buffer~ ::

    If the target file was not yet visited when capture was invoked,
    kill the buffer again after capture is completed.

  - ~:no-save~ ::

    Do not save the target file after finishing the capture.

  - ~:refile-targets~ :: Temporarily set ~org-refile-targets~ to the
    value of this property.

  - ~:hook~ ::

    A nullary function or list of nullary functions run before
    ~org-capture-mode-hook~ when the template is selected.

 - ~:prepare-finalize~ ::

    A nullary function or list of nullary functions run before
    ~org-capture-prepare-finalize-hook~ when the template is selected.

 - ~:before-finalize~ ::

    A nullary function or list of nullary functions run before
    ~org-capture-before-finalize-hook~ when the template is selected.

 - ~:after-finalize~ ::

    A nullary function or list of nullary functions run before
    ~org-capture-after-finalize-hook~ when the template is selected.

**** Template expansion
:PROPERTIES:
:DESCRIPTION: Filling in information about time and context.
:END:

In the template itself, special "%-escapes"[fn:: If you need one of
these sequences literally, escape the =%= with a backslash.] allow
dynamic insertion of content.  The templates are expanded in the order
given here:

- =%[FILE]= ::

  Insert the contents of the file given by {{{var(FILE)}}}.

- =%(EXP)= ::

  Evaluate Elisp expression {{{var(EXP)}}} and replace it with the
  result.  The {{{var(EXP)}}} form must return a string.  Only
  placeholders pre-existing within the template, or introduced with
  =%[file]=, are expanded this way.  Since this happens after
  expanding non-interactive "%-escapes", those can be used to fill the
  expression.

- =%<FORMAT>= ::

  The result of format-time-string on the {{{var(FORMAT)}}}
  specification.

- =%t= ::

  Timestamp, date only.

- =%T= ::

  Timestamp, with date and time.

- =%u=, =%U= ::

  Like =%t=, =%T= above, but inactive timestamps.

- =%i= ::

  Initial content, the region when capture is called while the region
  is active.  If there is text before =%i= on the same line, such as
  indentation, and =%i= is not inside a =%(exp)= form, that prefix is
  added before every line in the inserted text.

- =%a= ::

  Annotation, normally the link created with ~org-store-link~.

- =%A= ::

  Like =%a=, but prompt for the description part.

- =%l= ::

  Like =%a=, but only insert the literal link.

- =%L= ::

  Like =%l=, but without brackets (the link content itself).

- =%c= ::

  Current kill ring head.

- =%x= ::

  Content of the X clipboard.

- =%k= ::

  Title of the currently clocked task.

- =%K= ::

  Link to the currently clocked task.

- =%n= ::

  User name (taken from ~user-full-name~).

- =%f= ::

  File visited by current buffer when org-capture was called.

- =%F= ::

  Full path of the file or directory visited by current buffer.

- =%:keyword= ::

  Specific information for certain link types, see below.

- =%^g= ::

  Prompt for tags, with completion on tags in target file.

- =%^G= ::

  Prompt for tags, with completion all tags in all agenda files.

- =%^t= ::

  Like =%t=, but prompt for date.  Similarly =%^T=, =%^u=, =%^U=.  You
  may define a prompt like =%^{Birthday}t=.

- =%^C= ::

  Interactive selection of which kill or clip to use.

- =%^L= ::

  Like =%^C=, but insert as link.

- =%^{PROP}p= ::

  Prompt the user for a value for property {{{var(PROP)}}}.  You may
  specify a default value with =%^{PROP|default}=.

- =%^{PROMPT}= ::

  Prompt the user for a string and replace this sequence with it.  You
  may specify a default value and a completion table with
  =%^{prompt|default|completion2|completion3...}=.  The arrow keys
  access a prompt-specific history.

- =%\N= ::

  Insert the text entered at the {{{var(N)}}}th =%^{PROMPT}=, where
  {{{var(N)}}} is a number, starting from 1.

- =%?= ::

  After completing the template, position point here.

#+vindex: org-store-link-props
For specific link types, the following keywords are defined[fn:: If
you define your own link types (see [[*Adding Hyperlink Types]]), any
property you store with ~org-store-link-props~ can be accessed in
capture templates in a similar way.]:

#+vindex: org-link-from-user-regexp
| Link type    | Available keywords                                       |
|--------------+----------------------------------------------------------|
| bbdb         | =%:name=, =%:company=                                    |
| irc          | =%:server=, =%:port=, =%:nick=                           |
| mh, rmail    | =%:type=, =%:subject=, =%:message-id=                    |
|              | =%:from=, =%:fromname=, =%:fromaddress=                  |
|              | =%:to=, =%:toname=, =%:toaddress=                        |
|              | =%:date= (message date header field)                     |
|              | =%:date-timestamp= (date as active timestamp)            |
|              | =%:date-timestamp-inactive= (date as inactive timestamp) |
|              | =%:fromto= (either "to NAME" or "from NAME")[fn:31]      |
| gnus         | =%:group=, for messages also all email fields            |
| w3, w3m      | =%:url=                                                  |
| info         | =%:file=, =%:node=                                       |
| calendar     | =%:date=                                                 |
| org-protocol | =%:link=, =%:description=, =%:annotation=                |

**** Templates in contexts
:PROPERTIES:
:DESCRIPTION: Only show a template in a specific context.
:END:

#+vindex: org-capture-templates-contexts
To control whether a capture template should be accessible from
a specific context, you can customize
~org-capture-templates-contexts~.  Let's say, for example, that you
have a capture template "p" for storing Gnus emails containing
patches.  Then you would configure this option like this:

#+begin_src emacs-lisp
(setq org-capture-templates-contexts
      '(("p" ((in-mode . "message-mode")))))
#+end_src

You can also tell that the command key {{{kbd(p)}}} should refer to
another template.  In that case, add this command key like this:

#+begin_src emacs-lisp
(setq org-capture-templates-contexts
      '(("p" "q" ((in-mode . "message-mode")))))
#+end_src

See the docstring of the variable for more information.

** Attachments
:PROPERTIES:
:DESCRIPTION: Attach files to outlines.
:END:
#+cindex: attachments

It is often useful to associate reference material with an outline
node.  Small chunks of plain text can simply be stored in the subtree
of a project.  Hyperlinks (see [[*Hyperlinks]]) can establish associations
with files that live elsewhere on a local, or even remote, computer,
like emails or source code files belonging to a project.

Another method is /attachments/, which are files located in a
directory belonging to an outline node.  Org uses directories either
named by a unique ID of each entry, or by a =DIR= property.

*** Attachment defaults and dispatcher
:PROPERTIES:
:DESCRIPTION: How to access attachment commands
:END:

By default, Org attach uses ID properties when adding attachments to
outline nodes.  This makes working with attachments fully automated.
There is no decision needed for folder-name or location.  ID-based
directories are by default located in the =data/= directory, which
lives in the same directory where your Org file lives[fn:: If you move
entries or Org files from one directory to another, you may want to
configure ~org-attach-id-dir~ to contain an absolute path.].

When attachments are made using ~org-attach~ a default tag =ATTACH= is
added to the node that gets the attachments.

For more control over the setup, see [[*Attachment options]].

The following commands deal with attachments:

- {{{kbd(C-c C-a)}}} (~org-attach~) ::

  #+kindex: C-c C-a
  #+findex: org-attach
  The dispatcher for commands related to the attachment system.  After
  these keys, a list of commands is displayed and you must press an
  additional key to select a command:

  - {{{kbd(a)}}} (~org-attach-attach~) ::

    #+kindex: C-c C-a a
    #+findex: org-attach-attach
    #+vindex: org-attach-method
    Select a file and move it into the task's attachment directory.
    The file is copied, moved, or linked, depending on
    ~org-attach-method~.  Note that hard links are not supported on
    all systems.

  - {{{kbd(c)}}}/{{{kbd(m)}}}/{{{kbd(l)}}} ::

    #+kindex: C-c C-a c
    #+kindex: C-c C-a m
    #+kindex: C-c C-a l
    Attach a file using the copy/move/link method.  Note that hard
    links are not supported on all systems.

  - {{{kbd(b)}}} (~org-attach-buffer~) ::

    #+kindex: C-c C-a b
    #+findex: org-attach-buffer
    Select a buffer and save it as a file in the task's attachment
    directory.

  - {{{kbd(n)}}} (~org-attach-new~) ::

    #+kindex: C-c C-a n
    #+findex: org-attach-new
    Create a new attachment as an Emacs buffer.

  - {{{kbd(z)}}} (~org-attach-sync~) ::

    #+kindex: C-c C-a z
    #+findex: org-attach-sync
    Synchronize the current task with its attachment directory, in
    case you added attachments yourself.

  - {{{kbd(o)}}} (~org-attach-open~) ::

    #+kindex: C-c C-a o
    #+findex: org-attach-open
    #+vindex: org-file-apps
    Open current task's attachment.  If there is more than one, prompt
    for a file name first.  Opening follows the rules set by
    ~org-file-apps~.  For more details, see the information on
    following hyperlinks (see [[*Handling Links]]).

  - {{{kbd(O)}}} (~org-attach-open-in-emacs~) ::

    #+kindex: C-c C-a O
    #+findex: org-attach-open-in-emacs
    Also open the attachment, but force opening the file in Emacs.

  - {{{kbd(f)}}} (~org-attach-reveal~) ::

    #+kindex: C-c C-a f
    #+findex: org-attach-reveal
    Open the current task's attachment directory.

  - {{{kbd(F)}}} (~org-attach-reveal-in-emacs~) ::

    #+kindex: C-c C-a F
    #+findex: org-attach-reveal-in-emacs
    Also open the directory, but force using Dired in Emacs.

  - {{{kbd(d)}}} (~org-attach-delete-one~) ::

    #+kindex: C-c C-a d
    Select and delete a single attachment.

  - {{{kbd(D)}}} (~org-attach-delete-all~) ::

    #+kindex: C-c C-a D
    Delete all of a task's attachments.  A safer way is to open the
    directory in Dired and delete from there.

  - {{{kbd(s)}}} (~org-attach-set-directory~) ::

    #+kindex: C-c C-a s
    #+cindex: @samp{DIR}, property
    Set a specific directory as the entry's attachment directory.
    This works by putting the directory path into the =DIR=
    property.

  - {{{kbd(S)}}} (~org-attach-unset-directory~) ::

    #+kindex: C-c C-a S
    #+cindex: @samp{DIR}, property
    Remove the attachment directory.  This command removes the =DIR=
    property and asks the user to either move content inside that
    folder, if an =ID= property is set, delete the content, or to
    leave the attachment directory as is but no longer attached to the
    outline node.

*** Attachment options
:PROPERTIES:
:DESCRIPTION: Configuring the attachment system
:END:

There are a couple of options for attachments that are worth
mentioning.

- ~org-attach-id-dir~ ::
  #+vindex: org-attach-id-dir
  The directory where attachments are stored when =ID= is used as
  method.

- ~org-attach-dir-relative~ ::
  #+vindex: org-attach-dir-relative
  When setting the =DIR= property on a node using {{{kbd(C-c C-a s)}}}
  (~org-attach-set-directory~), absolute links are entered by default.
  This option changes that to relative links.

- ~org-attach-use-inheritance~ ::
  #+vindex: org-attach-use-inheritance
  By default folders attached to an outline node are inherited from
  parents according to ~org-use-property-inheritance~.  If one instead
  want to set inheritance specifically for Org attach that can be done
  using ~org-attach-use-inheritance~.  Inheriting documents through
  the node hierarchy makes a lot of sense in most cases.  Especially
  when using attachment links (see [[*Attachment links]]).  The following
  example shows one use case for attachment inheritance:

  #+begin_example
  ,* Chapter A ...
    :PROPERTIES:
    :DIR: Chapter A/
    :END:
  ,** Introduction
  Some text

  #+NAME: Image 1
  [[attachment:image 1.jpg]]
  #+end_example

  Without inheritance one would not be able to resolve the link to
  =image 1.jpg=, since the link is inside a sub-heading to =Chapter
  A=.

  Inheritance works the same way for both =ID= and =DIR= property.  If
  both properties are defined on the same headline then =DIR= takes
  precedence.  This is also true if inheritance is enabled.  If =DIR=
  is inherited from a parent node in the outline, that property still
  takes precedence over an =ID= property defined on the node itself.

- ~org-attach-method~ ::
  #+vindex: org-attach-method
  When attaching files using the dispatcher {{{kbd(C-c C-a)}}} it
  defaults to copying files.  The behavior can be changed by
  customizing ~org-attach-method~.  Options are Copy, Move/Rename,
  Hard link or Symbolic link.

- ~org-attach-preferred-new-method~ ::
  #+vindex: org-attach-preferred-new-method
  This customization lets you choose the default way to attach to
  nodes without existing =ID= and =DIR= property.  It defaults to ~id~
  but can also be set to ~dir~, ~ask~ or ~nil~.

- ~org-attach-archive-delete~ ::
  #+vindex: org-attach-archive-delete
  Configure this to determine if attachments should be deleted or not
  when a subtree that has attachments is archived.

- ~org-attach-auto-tag~ ::
  #+vindex: org-attach-auto-tag
  When attaching files to a heading it will be assigned a tag
  according to what is set here.

- ~org-attach-id-to-path-function-list~ ::
  #+vindex: org-attach-id-to-path-function-list
  When =ID= is used for attachments, the ID is parsed into a part of a
  directory-path.  See ~org-attach-id-uuid-folder-format~ for the
  default function.  Define a new one and add it as first element in
  ~org-attach-id-to-path-function-list~ if you want the folder
  structure in any other way.  All functions in this list will be
  tried when resolving existing ID's into paths, to maintain backward
  compatibility with existing folders in your system.

- ~org-attach-store-link-p~ ::
  #+vindex: org-attach-store-link-p
  Stores a link to the file that is being attached.  The link is
  stored in ~org-stored-links~ for later insertion with {{{kbd(C-c
  C-l)}}} (see [[*Handling Links]]).  Depending on what option is set in
  ~org-attach-store-link-p~, the link is stored to either the original
  location as a file link, the attachment location as an attachment
  link or to the attachment location as a file link.

- ~org-attach-commands~ ::
  #+vindex: org-attach-commands
  List of all commands used in the attach dispatcher.

- ~org-attach-expert~ ::
  #+vindex: org-attach-expert
  Do not show the splash buffer with the attach dispatcher when
  ~org-attach-expert~ is set to non-~nil~.

See customization group =Org Attach= if you want to change the
default settings.

*** Attachment links
:PROPERTIES:
:DESCRIPTION: Hyperlink access to attachments
:END:

Attached files and folders can be referenced using attachment links.
This makes it easy to refer to the material added to an outline node.
Especially if it was attached using the unique ID of the entry!

#+begin_example
,* TODO Some task
  :PROPERTIES:
  :ID:       95d50008-c12e-479f-a4f2-cc0238205319
  :END:
See attached document for more information: [[attachment:info.org]]
#+end_example

See [[*External Links]] for more information about these links.

*** Automatic version-control with Git
:PROPERTIES:
:DESCRIPTION: Everything safely stored away
:END:

If the directory attached to an outline node is a Git repository, Org
can be configured to automatically commit changes to that repository
when it sees them.

To make Org mode take care of versioning of attachments for you, add
the following to your Emacs config:

#+begin_src emacs-lisp
(require 'org-attach-git)
#+end_src

*** Attach from Dired
:PROPERTIES:
:DESCRIPTION: Using dired to select an attachment
:END:
#+cindex: attach from Dired
#+findex: org-attach-dired-to-subtree

It is possible to attach files to a subtree from a Dired buffer.  To
use this feature, have one window in Dired mode containing the file(s)
to be attached and another window with point in the subtree that shall
get the attachments.  In the Dired window, with point on a file,
{{{kbd(M-x org-attach-dired-to-subtree)}}} attaches the file to the
subtree using the attachment method set by variable
~org-attach-method~.  When files are marked in the Dired window then
all marked files get attached.

Add the following lines to the Emacs init file to have {{{kbd(C-c C-x
a)}}} attach files in Dired buffers.

#+begin_src emacs-lisp
(add-hook 'dired-mode-hook
          (lambda ()
            (define-key dired-mode-map
              (kbd "C-c C-x a")
              #'org-attach-dired-to-subtree)))
#+end_src

The following code shows how to bind the previous command with
a specific attachment method.

#+begin_src emacs-lisp
(add-hook 'dired-mode-hook
          (lambda ()
            (define-key dired-mode-map (kbd "C-c C-x c")
              (lambda ()
                (interactive)
                (let ((org-attach-method 'cp))
                  (call-interactively #'org-attach-dired-to-subtree))))))
#+end_src

** RSS Feeds
:PROPERTIES:
:DESCRIPTION: Getting input from RSS feeds.
:END:
#+cindex: RSS feeds
#+cindex: Atom feeds

Org can add and change entries based on information found in RSS feeds
and Atom feeds.  You could use this to make a task out of each new
podcast in a podcast feed.  Or you could use a phone-based
note-creating service on the web to import tasks into Org.  To access
feeds, configure the variable ~org-feed-alist~.  The docstring of this
variable has detailed information.  With the following

#+begin_src emacs-lisp
(setq org-feed-alist
      '(("Slashdot"
         "https://rss.slashdot.org/Slashdot/slashdot"
         "~/txt/org/feeds.org" "Slashdot Entries")))
#+end_src

#+texinfo: @noindent
new items from the feed provided by =rss.slashdot.org= result in new
entries in the file =~/org/feeds.org= under the heading =Slashdot
Entries=, whenever the following command is used:

- {{{kbd(C-c C-x g)}}} (~org-feed-update-all~) ::

  #+kindex: C-c C-x g
  Collect items from the feeds configured in ~org-feed-alist~ and act
  upon them.

- {{{kbd(C-c C-x G)}}} (~org-feed-goto-inbox~) ::

  #+kindex: C-c C-x G
  Prompt for a feed name and go to the inbox configured for this feed.

Under the same headline, Org creates a drawer =FEEDSTATUS= in which it
stores information about the status of items in the feed, to avoid
adding the same item several times.

For more information, including how to read atom feeds, see
=org-feed.el= and the docstring of ~org-feed-alist~.

* Agenda Views
:PROPERTIES:
:DESCRIPTION: Collecting information into views.
:END:
#+cindex: agenda views

Due to the way Org works, TODO items, time-stamped items, and tagged
headlines can be scattered throughout a file or even a number of
files.  To get an overview of open action items, or of events that are
important for a particular date, this information must be collected,
sorted and displayed in an organized way.

Org can select items based on various criteria and display them in
a separate buffer.  Six different view types are provided:

- an /agenda/ that is like a calendar and shows information for
  specific dates,

- a /TODO list/ that covers all unfinished action items,

- a /match view/, showings headlines based on the tags, properties,
  and TODO state associated with them,

- a /text search view/ that shows all entries from multiple files that
  contain specified keywords,

- a /stuck projects view/ showing projects that currently do not move
  along, and

- /custom views/ that are special searches and combinations of
  different views.

The extracted information is displayed in a special /agenda buffer/.
This buffer is read-only, but provides commands to visit the
corresponding locations in the original Org files, and even to edit
these files remotely.

#+vindex: org-agenda-skip-comment-trees
#+vindex: org-agenda-skip-archived-trees
#+cindex: commented entries, in agenda views
#+cindex: archived entries, in agenda views
By default, the report ignores commented (see [[*Comment Lines]]) and
archived (see [[*Internal archiving]]) entries.  You can override this by
setting ~org-agenda-skip-comment-trees~ and
~org-agenda-skip-archived-trees~ to ~nil~.

#+vindex: org-agenda-window-setup
#+vindex: org-agenda-restore-windows-after-quit
Two variables control how the agenda buffer is displayed and whether
the window configuration is restored when the agenda exits:
~org-agenda-window-setup~ and ~org-agenda-restore-windows-after-quit~.

** Agenda Files
:PROPERTIES:
:DESCRIPTION: Files being searched for agenda information.
:END:
#+cindex: agenda files
#+cindex: files for agenda

#+vindex: org-agenda-files
The information to be shown is normally collected from all /agenda
files/, the files listed in the variable ~org-agenda-files~[fn:: If
the value of that variable is not a list, but a single file name, then
the list of agenda files in maintained in that external file.].  If a
directory is part of this list, all files with the extension =.org= in
this directory are part of the list.

Thus, even if you only work with a single Org file, that file should
be put into the list[fn:: When using the dispatcher, pressing
{{{kbd(<)}}} before selecting a command actually limits the command to
the current file, and ignores ~org-agenda-files~ until the next
dispatcher command.].  You can customize ~org-agenda-files~, but the
easiest way to maintain it is through the following commands

#+attr_texinfo: :sep and
- {{{kbd(C-c [)}}} (~org-agenda-file-to-front~) ::

  #+kindex: C-c [
  #+findex: org-agenda-file-to-front
  #+cindex: files, adding to agenda list
  Add current file to the list of agenda files.  The file is added to
  the front of the list.  If it was already in the list, it is moved
  to the front.  With a prefix argument, file is added/moved to the
  end.

- {{{kbd(C-c ])}}} (~org-remove-file~) ::

  #+kindex: C-c ]
  #+findex: org-remove-file
  Remove current file from the list of agenda files.

- {{{kbd(C-')}}} and {{{kbd(C-\,)}}} (~org-cycle-agenda-files~) ::

  #+kindex: C-'
  #+kindex: C-,
  #+findex: org-cycle-agenda-files
  #+cindex: cycling, of agenda files
  Cycle through agenda file list, visiting one file after the other.

- {{{kbd(M-x org-switchb)}}} ::

  #+findex: org-switchb
  Command to use an Iswitchb-like interface to switch to and between
  Org buffers.

#+texinfo: @noindent
The Org menu contains the current list of files and can be used to
visit any of them.

If you would like to focus the agenda temporarily on a file not in
this list, or on just one file in the list, or even on only a subtree
in a file, then this can be done in different ways.  For a single
agenda command, you may press {{{kbd(<)}}} once or several times in
the dispatcher (see [[*The Agenda Dispatcher]]).  To restrict the agenda
scope for an extended period, use the following commands:

- {{{kbd(C-c C-x <)}}} (~org-agenda-set-restriction-lock~) ::

  #+kindex: C-c C-x <
  #+findex: org-agenda-set-restriction-lock
  Restrict the agenda to the current subtree.  If there already is
  a restriction at point, remove it.  When called with a universal
  prefix argument or with point before the first headline in a file,
  set the agenda scope to the entire file.  This restriction remains
  in effect until removed with {{{kbd(C-c C-x >)}}}, or by typing
  either {{{kbd(<)}}} or {{{kbd(>)}}} in the agenda dispatcher.  If
  there is a window displaying an agenda view, the new restriction
  takes effect immediately.

- {{{kbd(C-c C-x >)}}} (~org-agenda-remove-restriction-lock~) ::

  #+kindex: C-c C-x >
  #+findex: org-agenda-remove-restriction-lock
  Remove the restriction created by {{{kbd(C-c C-x <)}}}.

When working with Speedbar, you can use the following commands in the
Speedbar frame:

- {{{kbd(<)}}} (~org-speedbar-set-agenda-restriction~) ::

  #+findex: org-speedbar-set-agenda-restriction
  Restrict the agenda to the item---either an Org file or a subtree in
  such a file---at point in the Speedbar frame.  If agenda is already
  restricted there, remove the restriction.  If there is a window
  displaying an agenda view, the new restriction takes effect
  immediately.

- {{{kbd(>)}}} (~org-agenda-remove-restriction-lock~) ::

  #+findex: org-agenda-remove-restriction-lock
  Remove the restriction.

** The Agenda Dispatcher
:PROPERTIES:
:DESCRIPTION: Keyboard access to agenda views.
:ALT_TITLE: Agenda Dispatcher
:END:
#+cindex: agenda dispatcher
#+cindex: dispatching agenda commands

The views are created through a dispatcher, accessible with {{{kbd(M-x
org-agenda)}}}, or, better, bound to a global key (see [[*Activation]]).
It displays a menu from which an additional letter is required to
execute a command.  The dispatcher offers the following default
commands:

#+attr_texinfo: :sep ,
- {{{kbd(a)}}} ::

  Create the calendar-like agenda (see [[*Weekly/daily agenda]]).

- {{{kbd(t)}}}, {{{kbd(T)}}} ::

  Create a list of all TODO items (see [[*The global TODO list]]).

- {{{kbd(m)}}}, {{{kbd(M)}}} ::

  Create a list of headlines matching a given expression (see
  [[*Matching tags and properties]]).

- {{{kbd(s)}}} ::

  #+kindex: s @r{(Agenda dispatcher)}
  Create a list of entries selected by a boolean expression of
  keywords and/or regular expressions that must or must not occur in
  the entry.

- {{{kbd(/)}}} ::

  #+kindex: / @r{(Agenda dispatcher)}
  #+vindex: org-agenda-text-search-extra-files
  Search for a regular expression in all agenda files and additionally
  in the files listed in ~org-agenda-text-search-extra-files~.  This
  uses the Emacs command ~multi-occur~.  A prefix argument can be used
  to specify the number of context lines for each match, the default
  is 1.

- {{{kbd(#)}}} ::

  Create a list of stuck projects (see [[*Stuck projects]]).

- {{{kbd(!)}}} ::

  Configure the list of stuck projects (see [[*Stuck projects]]).

- {{{kbd(<)}}} ::

  #+kindex: < @r{(Agenda dispatcher)}
  Restrict an agenda command to the current buffer[fn:: For backward
  compatibility, you can also press {{{kbd(1)}}} to restrict to the
  current buffer.].  If narrowing is in effect restrict to the
  narrowed part of the buffer.  After pressing {{{kbd(<)}}}, you still
  need to press the character selecting the command.

- {{{kbd(< <)}}} ::

  #+kindex: < < @r{(Agenda dispatcher)}
  If there is an active region, restrict the following agenda command
  to the region.  Otherwise, restrict it to the current subtree[fn::
  For backward compatibility, you can also press {{{kbd(0)}}} to
  restrict to the current region/subtree.].  After pressing {{{kbd(<
  <)}}}, you still need to press the character selecting the command.

- {{{kbd(*)}}} ::

  #+kindex: * @r{(Agenda dispatcher)}
  #+vindex: org-agenda-sticky
  #+findex: org-toggle-sticky-agenda
  Toggle sticky agenda views.  By default, Org maintains only a single
  agenda buffer and rebuilds it each time you change the view, to make
  sure everything is always up to date.  If you switch between views
  often and the build time bothers you, you can turn on sticky agenda
  buffers (make this the default by customizing the variable
  ~org-agenda-sticky~).  With sticky agendas, the dispatcher only
  switches to the selected view, you need to update it by hand with
  {{{kbd(r)}}} or {{{kbd(g)}}}.  You can toggle sticky agenda view any
  time with ~org-toggle-sticky-agenda~.

You can also define custom commands that are accessible through the
dispatcher, just like the default commands.  This includes the
possibility to create extended agenda buffers that contain several
blocks together, for example the weekly agenda, the global TODO list
and a number of special tags matches.  See [[*Custom Agenda Views]].

** The Built-in Agenda Views
:PROPERTIES:
:DESCRIPTION: What is available out of the box?
:ALT_TITLE: Built-in Agenda Views
:END:

In this section we describe the built-in views.

*** Weekly/daily agenda
:PROPERTIES:
:DESCRIPTION: The calendar page with current tasks.
:END:
#+cindex: agenda
#+cindex: weekly agenda
#+cindex: daily agenda

The purpose of the weekly/daily /agenda/ is to act like a page of
a paper agenda, showing all the tasks for the current week or day.

- {{{kbd(M-x org-agenda a)}}} (~org-agenda-list~) ::

  #+kindex: a @r{(Agenda dispatcher)}
  #+findex: org-agenda-list
  #+cindex: org-agenda, command
  Compile an agenda for the current week from a list of Org files.
  The agenda shows the entries for each day.  With a numeric prefix
  argument[fn:32]---like {{{kbd(C-u 2 1 M-x org-agenda a)}}}---you may
  set the number of days to be displayed.

#+vindex: org-agenda-span
#+vindex: org-agenda-start-day
#+vindex: org-agenda-start-on-weekday
The default number of days displayed in the agenda is set by the
variable ~org-agenda-span~.  This variable can be set to any number of
days you want to see by default in the agenda, or to a span name, such
a ~day~, ~week~, ~month~ or ~year~.  For weekly agendas, the default
is to start on the previous Monday (see
~org-agenda-start-on-weekday~).  You can also set the start date using
a date shift: =(setq org-agenda-start-day "+10d")= starts the agenda
ten days from today in the future.  ~org-agenda-start-on-weekday~
takes precedence over ~org-agenda-start-day~ in weekly and bi-weekly
agendas.

Remote editing from the agenda buffer means, for example, that you can
change the dates of deadlines and appointments from the agenda buffer.
The commands available in the Agenda buffer are listed in [[*Commands in
the Agenda Buffer]].

**** Calendar/Diary integration
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: calendar integration
#+cindex: diary integration

Emacs contains the calendar and diary by Edward\nbsp{}M.\nbsp{}Reingold.  The
calendar displays a three-month calendar with holidays from different
countries and cultures.  The diary allows you to keep track of
anniversaries, lunar phases, sunrise/set, recurrent appointments
(weekly, monthly) and more.  In this way, it is quite complementary to
Org.  It can be very useful to combine output from Org with the diary.

In order to include entries from the Emacs diary into Org mode's
agenda, you only need to customize the variable

#+begin_src emacs-lisp
(setq org-agenda-include-diary t)
#+end_src

#+texinfo: @noindent
After that, everything happens automatically.  All diary entries
including holidays, anniversaries, etc., are included in the agenda
buffer created by Org mode.  {{{kbd(SPC)}}}, {{{kbd(TAB)}}}, and
{{{kbd(RET)}}} can be used from the agenda buffer to jump to the diary
file in order to edit existing diary entries.  The {{{kbd(i)}}}
command to insert new entries for the current date works in the agenda
buffer, as well as the commands {{{kbd(S)}}}, {{{kbd(M)}}}, and
{{{kbd(C)}}} to display Sunrise/Sunset times, show lunar phases and to
convert to other calendars, respectively.  {{{kbd(c)}}} can be used to
switch back and forth between calendar and agenda.

If you are using the diary only for expression entries and holidays,
it is faster to not use the above setting, but instead to copy or even
move the entries into an Org file.  Org mode evaluates diary-style
expression entries, and does it faster because there is no overhead
for first creating the diary display.  Note that the expression
entries must start at the left margin, no whitespace is allowed before
them, as seen in the following segment of an Org file:[fn:: The
variable ~org-anniversary~ used in the example is just like
~diary-anniversary~, but the argument order is always according to ISO
and therefore independent of the value of ~calendar-date-style~.]

#+begin_example
,* Holidays
  :PROPERTIES:
  :CATEGORY: Holiday
  :END:
%%(org-calendar-holiday)   ; special function for holiday names

,* Birthdays
  :PROPERTIES:
  :CATEGORY: Ann
  :END:
%%(org-anniversary 1956  5 14) Arthur Dent is %d years old
%%(org-anniversary 1869 10  2) Mahatma Gandhi would be %d years old
#+end_example

**** Anniversaries from BBDB
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: BBDB, anniversaries
#+cindex: anniversaries, from BBDB

#+findex: org-bbdb-anniversaries
If you are using the Insidious Big Brother Database to store your
contacts, you very likely prefer to store anniversaries in BBDB rather
than in a separate Org or diary file.  Org supports this and can show
BBDB anniversaries as part of the agenda.  All you need to do is to
add the following to one of your agenda files:

#+begin_example
,* Anniversaries
  :PROPERTIES:
  :CATEGORY: Anniv
  :END:
%%(org-bbdb-anniversaries)
#+end_example

You can then go ahead and define anniversaries for a BBDB record.
Basically, you need a field named =anniversary= for the BBDB record
which contains the date in the format =YYYY-MM-DD= or =MM-DD=,
followed by a space and the class of the anniversary (=birthday=,
=wedding=, or a format string).  If you omit the class, it defaults to
=birthday=.  Here are a few examples, the header for the file
=ol-bbdb.el= contains more detailed information.

#+begin_example
1973-06-22
06-22
1955-08-02 wedding
2008-04-14 %s released version 6.01 of Org mode, %d years ago
#+end_example

After a change to BBDB, or for the first agenda display during an
Emacs session, the agenda display suffers a short delay as Org updates
its hash with anniversaries.  However, from then on things will be
very fast, much faster in fact than a long list of
=%%(diary-anniversary)= entries in an Org or Diary file.

#+findex: org-bbdb-anniversaries-future
If you would like to see upcoming anniversaries with a bit of
forewarning, you can use the following instead:

#+begin_example
,* Anniversaries
  :PROPERTIES:
  :CATEGORY: Anniv
  :END:
%%(org-bbdb-anniversaries-future 3)
#+end_example

That will give you three days' warning: on the anniversary date itself
and the two days prior.  The argument is optional: if omitted, it
defaults to 7.

**** Appointment reminders
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: @file{appt.el}
#+cindex: appointment reminders
#+cindex: appointment
#+cindex: reminders

#+cindex: APPT_WARNTIME, keyword
Org can interact with Emacs appointments notification facility.  To
add the appointments of your agenda files, use the command
~org-agenda-to-appt~.  This command lets you filter through the list
of your appointments and add only those belonging to a specific
category or matching a regular expression.  It also reads
a =APPT_WARNTIME= property which overrides the value of
~appt-message-warning-time~ for this appointment.  See the docstring
for details.

*** The global TODO list
:PROPERTIES:
:DESCRIPTION: All unfinished action items.
:ALT_TITLE: Global TODO list
:END:
#+cindex: global TODO list
#+cindex: TODO list, global

The global TODO list contains all unfinished TODO items formatted and
collected into a single place.

- {{{kbd(M-x org-agenda t)}}} (~org-todo-list~) ::

  #+kindex: t @r{(Agenda dispatcher)}
  #+findex: org-todo-list
  Show the global TODO list.  This collects the TODO items from all
  agenda files (see [[*Agenda Views]]) into a single buffer.  By default,
  this lists items with a state that is not a DONE state.  The buffer
  is in Agenda mode, so there are commands to examine and manipulate
  the TODO entries directly from that buffer (see [[*Commands in the
  Agenda Buffer]]).

- {{{kbd(M-x org-agenda T)}}} (~org-todo-list~) ::

  #+kindex: T @r{(Agenda dispatcher)}
  #+findex: org-todo-list
  #+cindex: TODO keyword matching
  #+vindex: org-todo-keywords
  Like the above, but allows selection of a specific TODO keyword.
  You can also do this by specifying a prefix argument to
  {{{kbd(t)}}}.  You are prompted for a keyword, and you may also
  specify several keywords by separating them with =|= as the boolean
  OR operator.  With a numeric prefix, the Nth keyword in
  ~org-todo-keywords~ is selected.

  #+kindex: r
  The {{{kbd(r)}}} key in the agenda buffer regenerates it, and you
  can give a prefix argument to this command to change the selected
  TODO keyword, for example {{{kbd(3 r)}}}.  If you often need
  a search for a specific keyword, define a custom command for it (see
  [[*The Agenda Dispatcher]]).

  Matching specific TODO keywords can also be done as part of a tags
  search (see [[*Tag Searches]]).

Remote editing of TODO items means that you can change the state of
a TODO entry with a single key press.  The commands available in the
TODO list are described in [[*Commands in the Agenda Buffer]].

#+cindex: sublevels, inclusion into TODO list
Normally the global TODO list simply shows all headlines with TODO
keywords.  This list can become very long.  There are two ways to keep
it more compact:

-
  #+vindex: org-agenda-todo-ignore-scheduled
  #+vindex: org-agenda-todo-ignore-deadlines
  #+vindex: org-agenda-todo-ignore-timestamp
  #+vindex: org-agenda-todo-ignore-with-date
  Some people view a TODO item that has been /scheduled/ for execution
  or have a /deadline/ (see [[*Timestamps]]) as no longer /open/.
  Configure the variables ~org-agenda-todo-ignore-scheduled~ to
  exclude some or all scheduled items from the global TODO list,
  ~org-agenda-todo-ignore-deadlines~ to exclude some or all items with
  a deadline set, ~org-agenda-todo-ignore-timestamp~ to exclude some
  or all items with an active timestamp other than a DEADLINE or
  a SCHEDULED timestamp and/or ~org-agenda-todo-ignore-with-date~ to
  exclude items with at least one active timestamp.

-
  #+vindex: org-agenda-todo-list-sublevels
  TODO items may have sublevels to break up the task into subtasks.
  In such cases it may be enough to list only the highest level TODO
  headline and omit the sublevels from the global list.  Configure the
  variable ~org-agenda-todo-list-sublevels~ to get this behavior.

*** Matching tags and properties
:PROPERTIES:
:DESCRIPTION: Structured information with fine-tuned search.
:END:
#+cindex: matching, of tags
#+cindex: matching, of properties
#+cindex: tags view
#+cindex: match view

If headlines in the agenda files are marked with /tags/ (see [[*Tags]]),
or have properties (see [[*Properties and Columns]]), you can select
headlines based on this metadata and collect them into an agenda
buffer.  The match syntax described here also applies when creating
sparse trees with {{{kbd(C-c / m)}}}.

- {{{kbd(M-x org-agenda m)}}} (~org-tags-view~) ::

  #+kindex: m @r{(Agenda dispatcher)}
  #+findex: org-tags-view
  Produce a list of all headlines that match a given set of tags.  The
  command prompts for a selection criterion, which is a boolean logic
  expression with tags, like =+work+urgent-withboss= or =work|home=
  (see [[*Tags]]).  If you often need a specific search, define a custom
  command for it (see [[*The Agenda Dispatcher]]).

- {{{kbd(M-x org-agenda M)}}} (~org-tags-view~) ::

  #+kindex: M @r{(Agenda dispatcher)}
  #+findex: org-tags-view
  #+vindex: org-tags-match-list-sublevels
  #+vindex: org-agenda-tags-todo-honor-ignore-options
  Like {{{kbd(m)}}}, but only select headlines that are also TODO
  items and force checking subitems (see the variable
  ~org-tags-match-list-sublevels~).  To exclude scheduled/deadline
  items, see the variable ~org-agenda-tags-todo-honor-ignore-options~.
  Matching specific TODO keywords together with a tags match is also
  possible, see [[*Tag Searches]].

The commands available in the tags list are described in [[*Commands in
the Agenda Buffer]].

#+cindex: boolean logic, for agenda searches
A search string can use Boolean operators =&= for AND and =|= for OR.
=&= binds more strongly than =|=.  Parentheses are currently not
implemented.  Each element in the search is either a tag, a regular
expression matching tags, or an expression like =PROPERTY OPERATOR
VALUE= with a comparison operator, accessing a property value.  Each
element may be preceded by =-= to select against it, and =+= is
syntactic sugar for positive selection.  The AND operator =&= is
optional when =+= or =-= is present.  Here are some examples, using
only tags.

- =+work-boss= ::

  Select headlines tagged =work=, but discard those also tagged
  =boss=.

- =work|laptop= ::

  Selects lines tagged =work= or =laptop=.

- =work|laptop+night= ::

  Like before, but require the =laptop= lines to be tagged also
  =night=.

#+cindex: regular expressions, with tags search
Instead of a tag, you may also specify a regular expression enclosed
in curly braces (see [[*Regular Expressions]]).  For example,
=work+{^boss.*}= matches headlines that contain the tag =:work:= and
any tag /starting/ with =boss=.

#+cindex: group tags, as regular expressions
Group tags (see [[*Tag Hierarchy]]) are expanded as regular expressions.
E.g., if =work= is a group tag for the group =:work:lab:conf:=, then
searching for =work= also searches for ={\(?:work\|lab\|conf\)}= and
searching for =-work= searches for all headlines but those with one of
the tags in the group (i.e., =-{\(?:work\|lab\|conf\)}=).

#+cindex: TODO keyword matching, with tags search
#+cindex: level, for tags/property match
#+cindex: category, for tags/property match
#+vindex: org-odd-levels-only
You may also test for properties (see [[*Properties and Columns]]) at the
same time as matching tags.  The properties may be real properties, or
special properties that represent other metadata (see [[*Special
Properties]]).  For example, the property =TODO= represents the TODO
keyword of the entry.  Or, the property =LEVEL= represents the level
of an entry.  So searching =+LEVEL=3+boss-TODO​="DONE"= lists all level
three headlines that have the tag =boss= and are /not/ marked with the
TODO keyword =DONE=.  In buffers with ~org-odd-levels-only~ set,
=LEVEL= does not count the number of stars, but =LEVEL=2= corresponds
to 3 stars etc.

Here are more examples:

- =work+TODO​="WAITING"= ::

  Select =work=-tagged TODO lines with the specific TODO keyword
  =WAITING=.

- =work+TODO​="WAITING"|home+TODO​="WAITING"= ::

  Waiting tasks both at work and at home.

When matching properties, a number of different operators can be used
to test the value of a property.  Here is a complex example:

#+begin_example
+work-boss+PRIORITY="A"+Coffee="unlimited"+Effort<2
         +With={Sarah\|Denny}+SCHEDULED>="<2008-10-11>"
#+end_example

#+texinfo: @noindent
The type of comparison depends on how the comparison value is written:

- If the comparison value is a plain number, a numerical comparison is
  done, and the allowed operators are =<=, ===, =>=, =<==, =>==, and
  =<>=.

- If the comparison value is enclosed in double-quotes, a string
  comparison is done, and the same operators are allowed.

- If the comparison value is enclosed in double-quotes /and/ angular
  brackets (like =DEADLINE<​="<2008-12-24 18:30>"=), both values are
  assumed to be date/time specifications in the standard Org way, and
  the comparison is done accordingly.  Valid values also include
  ="<now>"= for now (including time), ="<today>"=, and ="<tomorrow>"=
  for these days at 0:00 hours, i.e., without a time specification.
  You can also use strings like ="<+5d>"= or ="<-2m>"= with units =d=,
  =w=, =m=, and =y= for day, week, month, and year, respectively.

- If the comparison value is enclosed in curly braces, a regexp match
  is performed, with === meaning that the regexp matches the property
  value, and =<>= meaning that it does not match.

So the search string in the example finds entries tagged =work= but
not =boss=, which also have a priority value =A=, a =Coffee= property
with the value =unlimited=, an =EFFORT= property that is numerically
smaller than 2, a =With= property that is matched by the regular
expression =Sarah\|Denny=, and that are scheduled on or after October
11, 2008.

You can configure Org mode to use property inheritance during
a search, but beware that this can slow down searches considerably.
See [[*Property Inheritance]], for details.

For backward compatibility, and also for typing speed, there is also
a different way to test TODO states in a search.  For this, terminate
the tags/property part of the search string (which may include several
terms connected with =|=) with a =/= and then specify a Boolean
expression just for TODO keywords.  The syntax is then similar to that
for tags, but should be applied with care: for example, a positive
selection on several TODO keywords cannot meaningfully be combined
with boolean AND.  However, /negative selection/ combined with AND can
be meaningful.  To make sure that only lines are checked that actually
have any TODO keyword (resulting in a speed-up), use {{{kbd(M-x
org-agenda M)}}}, or equivalently start the TODO part after the slash
with =!=.  Using {{{kbd(M-x org-agenda M)}}} or =/!= does not match
TODO keywords in a DONE state.  Examples:

- =work/WAITING= ::

  Same as =work+TODO​="WAITING"=.

- =work/!-WAITING-NEXT= ::

  Select =work=-tagged TODO lines that are neither =WAITING= nor
  =NEXT=.

- =work/!+WAITING|+NEXT= ::

  Select =work=-tagged TODO lines that are either =WAITING= or =NEXT=.

*** Search view
:PROPERTIES:
:DESCRIPTION: Find entries by searching for text.
:END:
#+cindex: search view
#+cindex: text search
#+cindex: searching, for text

This agenda view is a general text search facility for Org mode
entries.  It is particularly useful to find notes.

- {{{kbd(M-x org-agenda s)}}} (~org-search-view~) ::

  #+kindex: s @r{(Agenda dispatcher)}
  #+findex: org-search-view
  This is a special search that lets you select entries by matching
  a substring or specific words using a boolean logic.

For example, the search string =computer equipment= matches entries
that contain =computer equipment= as a substring, even if the two
words are separated by more space or a line break.

Search view can also search for specific keywords in the entry, using
Boolean logic.  The search string =+computer
+wifi -ethernet -{8\.11[bg]}= matches note entries that contain the
keywords =computer= and =wifi=, but not the keyword =ethernet=, and
which are also not matched by the regular expression =8\.11[bg]=,
meaning to exclude both =8.11b= and =8.11g=.  The first =+= is
necessary to turn on boolean search, other =+= characters are
optional.  For more details, see the docstring of the command
~org-search-view~.

You can incrementally and conveniently adjust a boolean search from
the agenda search view with the following keys

#+attr_texinfo: :columns 0.1 0.6
| {{{kbd([)}}} | Add a positive search word        |
| {{{kbd(])}}} | Add a negative search word        |
| {{{kbd({)}}} | Add a positive regular expression |
| {{{kbd(})}}} | Add a negative regular expression |

#+vindex: org-agenda-text-search-extra-files
Note that in addition to the agenda files, this command also searches
the files listed in ~org-agenda-text-search-extra-files~.

*** Stuck projects
:PROPERTIES:
:DESCRIPTION: Find projects you need to review.
:END:
#+pindex: GTD, Getting Things Done

If you are following a system like David Allen's GTD to organize your
work, one of the "duties" you have is a regular review to make sure
that all projects move along.  A /stuck/ project is a project that has
no defined next actions, so it never shows up in the TODO lists Org
mode produces.  During the review, you need to identify such projects
and define next actions for them.

- {{{kbd(M-x org-agenda #)}}} (~org-agenda-list-stuck-projects~) ::

  #+kindex: # @r{(Agenda dispatcher)}
  #+findex: org-agenda-list-stuck-projects
  List projects that are stuck.

- {{{kbd(M-x org-agenda !)}}} ::

  #+kindex: ! @r{(Agenda dispatcher)}
  #+vindex: org-stuck-projects
  Customize the variable ~org-stuck-projects~ to define what a stuck
  project is and how to find it.

You almost certainly need to configure this view before it works for
you.  The built-in default assumes that all your projects are level-2
headlines, and that a project is not stuck if it has at least one
entry marked with a TODO keyword =TODO= or =NEXT= or =NEXTACTION=.

Let's assume that you, in your own way of using Org mode, identify
projects with a tag =:PROJECT:=, and that you use a TODO keyword
=MAYBE= to indicate a project that should not be considered yet.
Let's further assume that the TODO keyword =DONE= marks finished
projects, and that =NEXT= and =TODO= indicate next actions.  The tag
=:@shop:= indicates shopping and is a next action even without the
NEXT tag.  Finally, if the project contains the special word =IGNORE=
anywhere, it should not be listed either.  In this case you would
start by identifying eligible projects with a tags/TODO match (see
[[*Tag Searches]]) =+PROJECT/-MAYBE-DONE=, and then check for =TODO=,
=NEXT=, =@shop=, and =IGNORE= in the subtree to identify projects that
are not stuck.  The correct customization for this is:

#+begin_src emacs-lisp
(setq org-stuck-projects
      '("+PROJECT/-MAYBE-DONE" ("NEXT" "TODO") ("@shop")
        "\\<IGNORE\\>"))
#+end_src

Note that if a project is identified as non-stuck, the subtree of this
entry is searched for stuck projects.

** Presentation and Sorting
:PROPERTIES:
:DESCRIPTION: How agenda items are prepared for display.
:END:
#+cindex: presentation, of agenda items

#+vindex: org-agenda-prefix-format
#+vindex: org-agenda-tags-column
Before displaying items in an agenda view, Org mode visually prepares
the items and sorts them.  Each item occupies a single line.  The line
starts with a /prefix/ that contains the /category/ (see [[*Categories]])
of the item and other important information.  You can customize in
which column tags are displayed through ~org-agenda-tags-column~.  You
can also customize the prefix using the option
~org-agenda-prefix-format~.  This prefix is followed by a cleaned-up
version of the outline headline associated with the item.

*** Categories
:PROPERTIES:
:DESCRIPTION: Not all tasks are equal.
:END:
#+cindex: category
#+cindex: @samp{CATEGORY}, keyword

The category is a broad label assigned to each agenda item.  By
default, the category is simply derived from the file name, but you
can also specify it with a special line in the buffer, like
this:

: #+CATEGORY: Thesis

#+cindex: @samp{CATEGORY}, property
If you would like to have a special category for a single entry or
a (sub)tree, give the entry a =CATEGORY= property with the special
category you want to apply as the value.

#+vindex: org-agenda-category-icon-alist
The display in the agenda buffer looks best if the category is not
longer than 10 characters.  You can set up icons for category by
customizing the ~org-agenda-category-icon-alist~ variable.

*** Time-of-day specifications
:PROPERTIES:
:DESCRIPTION: How the agenda knows the time.
:END:
#+cindex: time-of-day specification

Org mode checks each agenda item for a time-of-day specification.  The
time can be part of the timestamp that triggered inclusion into the
agenda, for example

: <2005-05-10 Tue 19:00>

#+texinfo: @noindent
Time ranges can be specified with two timestamps:

: <2005-05-10 Tue 20:30>--<2005-05-10 Tue 22:15>

#+vindex: org-agenda-search-headline-for-time
In the headline of the entry itself, a time(range)---like =12:45= or a
=8:30-1pm=---may also appear as plain text[fn:: You can, however,
disable this by setting ~org-agenda-search-headline-for-time~ variable
to a ~nil~ value.].

If the agenda integrates the Emacs diary (see [[*Weekly/daily agenda]]),
time specifications in diary entries are recognized as well.

For agenda display, Org mode extracts the time and displays it in
a standard 24 hour format as part of the prefix.  The example times in
the previous paragraphs would end up in the agenda like this:

#+begin_example
 8:30-13:00 Arthur Dent lies in front of the bulldozer
12:45...... Ford Prefect arrives and takes Arthur to the pub
19:00...... The Vogon reads his poem
20:30-22:15 Marvin escorts the Hitchhikers to the bridge
#+end_example

#+cindex: time grid
If the agenda is in single-day mode, or for the display of today, the
timed entries are embedded in a time grid, like

#+begin_example
 8:00...... ------------------
 8:30-13:00 Arthur Dent lies in front of the bulldozer
10:00...... ------------------
12:00...... ------------------
12:45...... Ford Prefect arrives and takes Arthur to the pub
14:00...... ------------------
16:00...... ------------------
18:00...... ------------------
19:00...... The Vogon reads his poem
20:00...... ------------------
20:30-22:15 Marvin escorts the Hitchhikers to the bridge
#+end_example

#+vindex: org-agenda-use-time-grid
#+vindex: org-agenda-time-grid
The time grid can be turned on and off with the variable
~org-agenda-use-time-grid~, and can be configured with
~org-agenda-time-grid~.

*** Sorting of agenda items
:PROPERTIES:
:DESCRIPTION: The order of things.
:END:
#+cindex: sorting, of agenda items
#+cindex: priorities, of agenda items

Before being inserted into a view, the items are sorted.  How this is
done depends on the type of view.

-
  #+vindex: org-agenda-files
  For the daily/weekly agenda, the items for each day are sorted.  The
  default order is to first collect all items containing an explicit
  time-of-day specification.  These entries are shown at the beginning
  of the list, as a /schedule/ for the day.  After that, items remain
  grouped in categories, in the sequence given by ~org-agenda-files~.
  Within each category, items are sorted by priority (see
  [[*Priorities]]), which is composed of the base priority (2000 for
  priority =A=, 1000 for =B=, and 0 for =C=), plus additional
  increments for overdue scheduled or deadline items.

- For the TODO list, items remain in the order of categories, but
  within each category, sorting takes place according to priority (see
  [[*Priorities]]).  The priority used for sorting derives from the
  priority cookie, with additions depending on how close an item is to
  its due or scheduled date.

- For tags matches, items are not sorted at all, but just appear in
  the sequence in which they are found in the agenda files.

#+vindex: org-agenda-sorting-strategy
Sorting can be customized using the variable
~org-agenda-sorting-strategy~, and may also include criteria based on
the estimated effort of an entry (see [[*Effort Estimates]]).

*** Filtering/limiting agenda items
:PROPERTIES:
:DESCRIPTION: Dynamically narrow the agenda.
:END:

#+vindex: org-agenda-category-filter-preset
#+vindex: org-agenda-tag-filter-preset
#+vindex: org-agenda-effort-filter-preset
#+vindex: org-agenda-regexp-filter-preset
Agenda built-in or custom commands are statically defined.  Agenda
filters and limits allow to flexibly narrow down the list of agenda
entries.

/Filters/ only change the visibility of items, are very fast and are
mostly used interactively[fn:33].  You can switch quickly between
different filters without having to recreate the agenda.  /Limits/ on
the other hand take effect before the agenda buffer is populated, so
they are mostly useful when defined as local variables within custom
agenda commands.

**** Filtering in the agenda
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: agenda filtering
#+cindex: filtering entries, in agenda
#+cindex: tag filtering, in agenda
#+cindex: category filtering, in agenda
#+cindex: top headline filtering, in agenda
#+cindex: effort filtering, in agenda
#+cindex: query editing, in agenda

The general filtering command is ~org-agenda-filter~, bound to
{{{kbd(/)}}}.  Before we introduce it, we describe commands for
individual filter types.  All filtering commands handle prefix
arguments in the same way:  A single {{{kbd(C-u)}}} prefix negates the
filter, so it removes lines selected by the filter.  A double prefix
adds the new filter condition to the one(s) already in place, so
filter elements are accumulated.

- {{{kbd(\)}}} (~org-agenda-filter-by-tag~) ::

  #+findex: org-agenda-filter-by-tag
  Filter the agenda view with respect to a tag.  You are prompted for
  a tag selection letter; {{{kbd(SPC)}}} means any tag at all.
  Pressing {{{kbd(TAB)}}} at that prompt offers completion to select a
  tag, including any tags that do not have a selection character.  The
  command then hides all entries that do not contain or inherit this
  tag.  Pressing {{{kbd(+)}}} or {{{kbd(-)}}} at the prompt switches
  between filtering for and against the next tag.  To clear the
  filter, press {{{kbd(\)}}} twice (once to call the command again,
  and once at the prompt).

- {{{kbd(<)}}} (~org-agenda-filter-by-category~) ::

  #+findex: org-agenda-filter-by-category
  Filter by category of the line at point, and show only entries with
  this category.  When called with a prefix argument, hide all entries
  with the category at point.  To clear the filter, call this command
  again by pressing {{{kbd(<)}}}.

- {{{kbd(=)}}} (~org-agenda-filter-by-regexp~) ::

  #+findex: org-agenda-filter-by-regexp
  Filter the agenda view by a regular expression: only show agenda
  entries matching the regular expression the user entered.  To clear
  the filter, call the command again by pressing {{{kbd(=)}}}.

- {{{kbd(_)}}} (~org-agenda-filter-by-effort~) ::

  #+findex: org-agenda-filter-by-effort
  Filter the agenda view with respect to effort estimates, so select
  tasks that take the right amount of time.  You first need to set up
  a list of efforts globally, for example

  #+begin_src emacs-lisp
  (setq org-global-properties
        '(("Effort_ALL". "0 0:10 0:30 1:00 2:00 3:00 4:00")))
  #+end_src

  #+vindex: org-sort-agenda-noeffort-is-high
  You can then filter for an effort by first typing an operator, one
  of {{{kbd(<)}}}, {{{kbd(>)}}} and {{{kbd(=)}}}, and then the
  one-digit index of an effort estimate in your array of allowed
  values, where {{{kbd(0)}}} means the 10th value.  The filter then
  restricts to entries with effort smaller-or-equal, equal, or
  larger-or-equal than the selected value.  For application of the
  operator, entries without a defined effort are treated according to
  the value of ~org-sort-agenda-noeffort-is-high~.  To clear the
  filter, press {{{kbd(_)}}} twice (once to call the command again,
  and once at the first prompt).

- {{{kbd(^)}}} (~org-agenda-filter-by-top-headline~) ::

  #+findex: org-agenda-filter-by-top-headline
  Filter the current agenda view and only display items that fall
  under the same top-level headline as the current entry.  To clear
  the filter, call this command again by pressing {{{kbd(^)}}}.

- {{{kbd(/)}}} (~org-agenda-filter~) ::

  #+findex: org-agenda-filter
  This is the unified interface to four of the five filter methods
  described above.  At the prompt, specify different filter elements
  in a single string, with full completion support.  For example,

  : +work-John+<0:10-/plot/

  selects entries with category =work= and effort estimates below 10
  minutes, and deselects entries with tag =John= or matching the
  regexp =plot= (see [[*Regular Expressions]]).  You can leave =+= out if
  that does not lead to ambiguities.  The sequence of elements is
  arbitrary.  The filter syntax assumes that there is no overlap
  between categories and tags.  Otherwise, tags take priority.  If you
  reply to the prompt with the empty string, all filtering is removed.
  If a filter is specified, it replaces all current filters.  But if
  you call the command with a double prefix argument, or if you add an
  additional =+= (e.g., =++work=) to the front of the string, the new
  filter elements are added to the active ones.  A single prefix
  argument applies the entire filter in a negative sense.

- {{{kbd(|)}}} (~org-agenda-filter-remove-all~) ::

  Remove all filters in the current agenda view.

**** Computed tag filtering
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+vindex: org-agenda-auto-exclude-function
If the variable ~org-agenda-auto-exclude-function~ is set to
a user-defined function, that function can select tags that should be
used as a tag filter when requested.  The function will be called with
lower-case versions of all tags represented in the current view.  The
function should return ="-tag"= if the filter should remove
entries with that tag, ="+tag"= if only entries with this tag should
be kept, or =nil= if that tag is irrelevant.  For example, let's say
you use a =Net= tag to identify tasks which need network access, an
=Errand= tag for errands in town, and a =Call= tag for making phone
calls.  You could auto-exclude these tags based on the availability of
the Internet, and outside of business hours, with something like this:

#+begin_src emacs-lisp
(defun my-auto-exclude-fn (tag)
  (when (cond ((string= tag "net")
               (/= 0 (call-process "/sbin/ping" nil nil nil
                                   "-c1" "-q" "-t1" "mail.gnu.org")))
              ((member tag '("errand" "call"))
               (let ((hr (nth 2 (decode-time))))
                 (or (< hr 8) (> hr 21)))))
    (concat "-" tag)))

(setq org-agenda-auto-exclude-function #'my-auto-exclude-fn)
#+end_src

You can apply this self-adapting filter by using a triple prefix
argument to ~org-agenda-filter~, i.e.\nbsp{}press {{{kbd(C-u C-u C-u /)}}},
or by pressing {{{kbd(RET)}}} in ~org-agenda-filter-by-tag~.

**** Setting limits for the agenda
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: limits, in agenda

Here is a list of options that you can set, either globally, or
locally in your custom agenda views (see [[*Custom Agenda Views]]).

- ~org-agenda-max-entries~ ::

  #+vindex: org-agenda-max-entries
  Limit the number of entries.

- ~org-agenda-max-effort~ ::

  #+vindex: org-agenda-max-effort
  Limit the duration of accumulated efforts (as minutes).

- ~org-agenda-max-todos~ ::

  #+vindex: org-agenda-max-todos
  Limit the number of entries with TODO keywords.

- ~org-agenda-max-tags~ ::

  #+vindex: org-agenda-max-tags
  Limit the number of tagged entries.

When set to a positive integer, each option excludes entries from
other categories: for example, =(setq org-agenda-max-effort 100)=
limits the agenda to 100 minutes of effort and exclude any entry that
has no effort property.  If you want to include entries with no effort
property, use a negative value for ~org-agenda-max-effort~.  One
useful setup is to use ~org-agenda-max-entries~ locally in a custom
command.  For example, this custom command displays the next five
entries with a =NEXT= TODO keyword.

#+begin_src emacs-lisp
(setq org-agenda-custom-commands
      '(("n" todo "NEXT"
         ((org-agenda-max-entries 5)))))
#+end_src

Once you mark one of these five entry as DONE, rebuilding the agenda
will again the next five entries again, including the first entry that
was excluded so far.

You can also dynamically set temporary limits, which are lost when
rebuilding the agenda:

- {{{kbd(~ )}}} (~org-agenda-limit-interactively~) ::

  #+findex: org-agenda-limit-interactively
  This prompts for the type of limit to apply and its value.

** Commands in the Agenda Buffer
:PROPERTIES:
:DESCRIPTION: Remote editing of Org trees.
:ALT_TITLE: Agenda Commands
:END:
#+cindex: commands, in agenda buffer

Entries in the agenda buffer are linked back to the Org file or diary
file where they originate.  You are not allowed to edit the agenda
buffer itself, but commands are provided to show and jump to the
original entry location, and to edit the Org files "remotely" from the
agenda buffer.  In this way, all information is stored only once,
removing the risk that your agenda and note files may diverge.

Some commands can be executed with mouse clicks on agenda lines.  For
the other commands, point needs to be in the desired line.

*** Motion
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: motion commands in agenda

- {{{kbd(n)}}} (~org-agenda-next-line~) ::

  #+kindex: n
  #+findex: org-agenda-next-line
  Next line (same as {{{kbd(DOWN)}}} and {{{kbd(C-n)}}}).

- {{{kbd(p)}}} (~org-agenda-previous-line~) ::

  #+kindex: p
  #+findex: org-agenda-previous-line
  Previous line (same as {{{kbd(UP)}}} and {{{kbd(C-p)}}}).

*** View/Go to Org file
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: view file commands in agenda

- {{{kbd(SPC)}}} or {{{kbd(mouse-3)}}} (~org-agenda-show-and-scroll-up~) ::

  #+kindex: SPC
  #+kindex: mouse-3
  #+findex: org-agenda-show-and-scroll-up
  Display the original location of the item in another window.
  With a prefix argument, make sure that drawers stay folded.

- {{{kbd(L)}}} (~org-agenda-recenter~) ::

  #+findex: org-agenda-recenter
  Display original location and recenter that window.

- {{{kbd(TAB)}}} or {{{kbd(mouse-2)}}} (~org-agenda-goto~) ::

  #+kindex: TAB
  #+kindex: mouse-2
  #+findex: org-agenda-goto
  Go to the original location of the item in another window.

- {{{kbd(RET)}}} (~org-agenda-switch-to~) ::

  #+kindex: RET
  #+findex: org-agenda-switch-to
  Go to the original location of the item and delete other windows.

- {{{kbd(F)}}} (~org-agenda-follow-mode~) ::

  #+kindex: F
  #+findex: org-agenda-follow-mode
  #+vindex: org-agenda-start-with-follow-mode
  Toggle Follow mode.  In Follow mode, as you move point through the
  agenda buffer, the other window always shows the corresponding
  location in the Org file.  The initial setting for this mode in new
  agenda buffers can be set with the variable
  ~org-agenda-start-with-follow-mode~.

- {{{kbd(C-c C-x b)}}} (~org-agenda-tree-to-indirect-buffer~) ::

  #+kindex: C-c C-x b
  #+findex: org-agenda-tree-to-indirect-buffer
  Display the entire subtree of the current item in an indirect
  buffer.  With a numeric prefix argument N, go up to level N and then
  take that tree.  If N is negative, go up that many levels.  With
  a {{{kbd(C-u)}}} prefix, do not remove the previously used indirect
  buffer.

- {{{kbd(C-c C-o)}}} (~org-agenda-open-link~) ::

  #+kindex: C-c C-o
  #+findex: org-agenda-open-link
  Follow a link in the entry.  This offers a selection of any links in
  the text belonging to the referenced Org node.  If there is only one
  link, follow it without a selection prompt.

*** Change display
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: change agenda display
#+cindex: display changing, in agenda

#+attr_texinfo: :sep ,
- {{{kbd(A)}}} ::

  #+kindex: A
  Interactively select another agenda view and append it to the
  current view.

- {{{kbd(o)}}} ::

  #+kindex: o
  Delete other windows.

- {{{kbd(v d)}}} or short {{{kbd(d)}}} (~org-agenda-day-view~) ::

  #+kindex: v d
  #+kindex: d
  #+findex: org-agenda-day-view
  Switch to day view.  When switching to day view, this setting
  becomes the default for subsequent agenda refreshes.  A numeric
  prefix argument may be used to jump directly to a specific day of
  the year.  For example, {{{kbd(32 d)}}} jumps to February 1st.  When
  setting day view, a year may be encoded in the prefix argument as
  well.  For example, {{{kbd(200712 d)}}} jumps to January 12, 2007.
  If such a year specification has only one or two digits, it is
  expanded into one of the 30 next years or the last 69 years.

- {{{kbd(v w)}}} or short {{{kbd(w)}}} (~org-agenda-week-view~) ::

  #+kindex: v w
  #+kindex: w
  #+findex: org-agenda-week-view
  Switch to week view.  When switching week view, this setting becomes
  the default for subsequent agenda refreshes.  A numeric prefix
  argument may be used to jump directly to a specific day of the ISO
  week.  For example {{{kbd(9 w)}}} to ISO week number 9.  When
  setting week view, a year may be encoded in the prefix argument as
  well.  For example, {{{kbd(200712 w)}}} jumps to week 12 in 2007.
  If such a year specification has only one or two digits, it is
  expanded into one of the 30 next years or the last 69 years.

- {{{kbd(v m)}}} (~org-agenda-month-view~) ::

  #+kindex: v m
  #+findex: org-agenda-month-view
  Switch to month view.  Because month views are slow to create, they
  do not become the default for subsequent agenda refreshes.
  A numeric prefix argument may be used to jump directly to a specific
  day of the month.  When setting month view, a year may be encoded in
  the prefix argument as well.  For example, {{{kbd(200712 m)}}} jumps
  to December, 2007.  If such a year specification has only one or two
  digits, it is expanded into one of the 30 next years or the last 69
  years.

- {{{kbd(v y)}}} (~org-agenda-year-view~) ::

  #+kindex: v y
  #+findex: org-agenda-year-view
  Switch to year view.  Because year views are slow to create, they do
  not become the default for subsequent agenda refreshes.  A numeric
  prefix argument may be used to jump directly to a specific day of
  the year.

- {{{kbd(v SPC)}}} (~org-agenda-reset-view~) ::

  #+kindex: v SPC
  #+findex: org-agenda-reset-view
  #+vindex: org-agenda-span
  Reset the current view to ~org-agenda-span~.

- {{{kbd(f)}}} (~org-agenda-later~) ::

  #+kindex: f
  #+findex: org-agenda-later
  Go forward in time to display the span following the current one.
  For example, if the display covers a week, switch to the following
  week.  With a prefix argument, repeat that many times.

- {{{kbd(b)}}} (~org-agenda-earlier~) ::

  #+kindex: b
  #+findex: org-agenda-earlier
  Go backward in time to display earlier dates.

- {{{kbd(.)}}} (~org-agenda-goto-today~) ::

  #+kindex: .
  #+findex: org-agenda-goto-today
  Go to today.

- {{{kbd(j)}}} (~org-agenda-goto-date~) ::

  #+kindex: j
  #+findex: org-agenda-goto-date
  Prompt for a date and go there.

- {{{kbd(J)}}} (~org-agenda-clock-goto~) ::

  #+kindex: J
  #+findex: org-agenda-clock-goto
  Go to the currently clocked-in task /in the agenda buffer/.

- {{{kbd(D)}}} (~org-agenda-toggle-diary~) ::

  #+kindex: D
  #+findex: org-agenda-toggle-diary
  Toggle the inclusion of diary entries.  See [[*Weekly/daily agenda]].

- {{{kbd(v l)}}} or {{{kbd(v L)}}} or short {{{kbd(l)}}} (~org-agenda-log-mode~) ::

  #+kindex: v l
  #+kindex: l
  #+kindex: v L
  #+findex: org-agenda-log-mode
  #+vindex: org-log-done
  #+vindex: org-agenda-log-mode-items
  Toggle Logbook mode.  In Logbook mode, entries that were marked as
  done while logging was on (see the variable ~org-log-done~) are
  shown in the agenda, as are entries that have been clocked on that
  day.  You can configure the entry types that should be included in
  log mode using the variable ~org-agenda-log-mode-items~.  When
  called with a {{{kbd(C-u)}}} prefix argument, show all possible
  logbook entries, including state changes.  When called with two
  prefix arguments {{{kbd(C-u C-u)}}}, show only logging information,
  nothing else.  {{{kbd(v L)}}} is equivalent to {{{kbd(C-u v l)}}}.

- {{{kbd(v [)}}} or short {{{kbd([)}}} (~org-agenda-manipulate-query-add~) ::

  #+kindex: v [
  #+kindex: [
  #+findex: org-agenda-manipulate-query-add
  Include inactive timestamps into the current view.  Only for
  weekly/daily agenda.

- {{{kbd(v a)}}} (~org-agenda-archives-mode~) ::

  #+kindex: v a
  #+findex: org-agenda-archives-mode
  Toggle Archives mode.  In Archives mode, trees that are archived
  (see [[*Internal archiving]]) are also scanned when producing the
  agenda.  To exit archives mode, press {{{kbd(v a)}}} again.

- {{{kbd(v A)}}} ::

  #+kindex: v A
  Toggle Archives mode.  Include all archive files as well.

- {{{kbd(v R)}}} or short {{{kbd(R)}}} (~org-agenda-clockreport-mode~) ::

  #+kindex: v R
  #+kindex: R
  #+findex: org-agenda-clockreport-mode
  #+vindex: org-agenda-start-with-clockreport-mode
  #+vindex: org-clock-report-include-clocking-task
  Toggle Clockreport mode.  In Clockreport mode, the daily/weekly
  agenda always shows a table with the clocked times for the time span
  and file scope covered by the current agenda view.  The initial
  setting for this mode in new agenda buffers can be set with the
  variable ~org-agenda-start-with-clockreport-mode~.  By using a
  prefix argument when toggling this mode (i.e., {{{kbd(C-u R)}}}),
  the clock table does not show contributions from entries that are
  hidden by agenda filtering[fn:: Only tags filtering is respected
  here, effort filtering is ignored.].  See also the variables
  ~org-clock-report-include-clocking-task~ and
  ~org-agenda-clock-report-header~.

- {{{kbd(v c)}}} ::

  #+kindex: v c
  #+vindex: org-agenda-clock-consistency-checks
  Show overlapping clock entries, clocking gaps, and other clocking
  problems in the current agenda range.  You can then visit clocking
  lines and fix them manually.  See the variable
  ~org-agenda-clock-consistency-checks~ for information on how to
  customize the definition of what constituted a clocking problem.  To
  return to normal agenda display, press {{{kbd(l)}}} to exit Logbook
  mode.

- {{{kbd(v E)}}} or short {{{kbd(E)}}} (~org-agenda-entry-text-mode~) ::

  #+kindex: v E
  #+kindex: E
  #+findex: org-agenda-entry-text-mode
  #+vindex: org-agenda-start-with-entry-text-mode
  #+vindex: org-agenda-entry-text-maxlines
  Toggle entry text mode.  In entry text mode, a number of lines from
  the Org outline node referenced by an agenda line are displayed
  below the line.  The maximum number of lines is given by the
  variable ~org-agenda-entry-text-maxlines~.  Calling this command
  with a numeric prefix argument temporarily modifies that number to
  the prefix value.

- {{{kbd(G)}}} (~org-agenda-toggle-time-grid~) ::

  #+kindex: G
  #+vindex: org-agenda-use-time-grid
  #+vindex: org-agenda-time-grid
  Toggle the time grid on and off.  See also the variables
  ~org-agenda-use-time-grid~ and ~org-agenda-time-grid~.

- {{{kbd(r)}}} (~org-agenda-redo~), {{{kbd(g)}}} ::

  #+kindex: r
  #+kindex: g
  #+findex: org-agenda-redo
  Recreate the agenda buffer, for example to reflect the changes after
  modification of the timestamps of items with {{{kbd(S-LEFT)}}} and
  {{{kbd(S-RIGHT)}}}.  When the buffer is the global TODO list,
  a prefix argument is interpreted to create a selective list for
  a specific TODO keyword.

- {{{kbd(C-x C-s)}}} or short {{{kbd(s)}}} (~org-save-all-org-buffers~) ::

  #+kindex: C-x C-s
  #+findex: org-save-all-org-buffers
  #+kindex: s
  Save all Org buffers in the current Emacs session, and also the
  locations of IDs.

- {{{kbd(C-c C-x C-c)}}} (~org-agenda-columns~) ::

  #+kindex: C-c C-x C-c
  #+findex: org-agenda-columns
  #+vindex: org-columns-default-format
  Invoke column view (see [[*Column View]]) in the agenda buffer.  The
  column view format is taken from the entry at point, or, if there is
  no entry at point, from the first entry in the agenda view.  So
  whatever the format for that entry would be in the original buffer
  (taken from a property, from a =COLUMNS= keyword, or from the
  default variable ~org-columns-default-format~) is used in the
  agenda.

- {{{kbd(C-c C-x >)}}} (~org-agenda-remove-restriction-lock~) ::

  #+kindex: C-c C-x >
  #+findex: org-agenda-remove-restriction-lock
  Remove the restriction lock on the agenda, if it is currently
  restricted to a file or subtree (see [[*Agenda Files]]).

- {{{kbd(M-UP)}}} (~org-agenda-drag-line-backward~) ::

  #+kindex: M-UP
  #+findex: org-agenda-drag-line-backward
  Drag the line at point backward one line.  With a numeric prefix
  argument, drag backward by that many lines.

  Moving agenda lines does not persist after an agenda refresh and
  does not modify the contributing Org files.

- {{{kbd(M-DOWN)}}} (~org-agenda-drag-line-forward~) ::

  #+kindex: M-DOWN
  #+findex: org-agenda-drag-line-forward
  Drag the line at point forward one line.  With a numeric prefix
  argument, drag forward by that many lines.

*** Remote editing
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: remote editing, from agenda

- {{{kbd(0--9)}}} ::

  Digit argument.

- {{{kbd(C-_)}}} (~org-agenda-undo~) ::

  #+kindex: C-_
  #+findex: org-agenda-undo
  #+cindex: undoing remote-editing events
  #+cindex: remote editing, undo
  Undo a change due to a remote editing command.  The change is undone
  both in the agenda buffer and in the remote buffer.

- {{{kbd(t)}}} (~org-agenda-todo~) ::

  #+kindex: t
  #+findex: org-agenda-todo
  Change the TODO state of the item, both in the agenda and in the
  original Org file.  A prefix arg is passed through to the ~org-todo~
  command, so for example a {{{kbd(C-u)}}} prefix are will trigger
  taking a note to document the state change.

- {{{kbd(C-S-RIGHT)}}} (~org-agenda-todo-nextset~) ::

  #+kindex: C-S-RIGHT
  #+findex: org-agenda-todo-nextset
  Switch to the next set of TODO keywords.

- {{{kbd(C-S-LEFT)}}}, ~org-agenda-todo-previousset~ ::

  #+kindex: C-S-LEFT
  Switch to the previous set of TODO keywords.

- {{{kbd(C-k)}}} (~org-agenda-kill~) ::

  #+kindex: C-k
  #+findex: org-agenda-kill
  #+vindex: org-agenda-confirm-kill
  Delete the current agenda item along with the entire subtree
  belonging to it in the original Org file.  If the text to be deleted
  remotely is longer than one line, the kill needs to be confirmed by
  the user.  See variable ~org-agenda-confirm-kill~.

- {{{kbd(C-c C-w)}}} (~org-agenda-refile~) ::

  #+kindex: C-c C-w
  #+findex: org-agenda-refile
  Refile the entry at point.

- {{{kbd(C-c C-x C-a)}}} or short {{{kbd(a)}}} (~org-agenda-archive-default-with-confirmation~) ::

  #+kindex: C-c C-x C-a
  #+kindex: a
  #+findex: org-agenda-archive-default-with-confirmation
  #+vindex: org-archive-default-command
  Archive the subtree corresponding to the entry at point using the
  default archiving command set in ~org-archive-default-command~.
  When using the {{{kbd(a)}}} key, confirmation is required.

- {{{kbd(C-c C-x a)}}} (~org-agenda-toggle-archive-tag~) ::

  #+kindex: C-c C-x a
  #+findex: org-agenda-toggle-archive-tag
  Toggle the archive tag (see [[*Internal archiving]]) for the current
  headline.

- {{{kbd(C-c C-x A)}}} (~org-agenda-archive-to-archive-sibling~) ::

  #+kindex: C-c C-x A
  #+findex: org-agenda-archive-to-archive-sibling
  Move the subtree corresponding to the current entry to its /archive
  sibling/.

- {{{kbd(C-c C-x C-s)}}} or short {{{kbd($)}}} (~org-agenda-archive~) ::

  #+kindex: C-c C-x C-s
  #+kindex: $
  #+findex: org-agenda-archive
  Archive the subtree corresponding to the current headline.  This
  means the entry is moved to the configured archive location, most
  likely a different file.

- {{{kbd(T)}}} (~org-agenda-show-tags~) ::

  #+kindex: T
  #+findex: org-agenda-show-tags
  #+vindex: org-agenda-show-inherited-tags
  Show all tags associated with the current item.  This is useful if
  you have turned off ~org-agenda-show-inherited-tags~, but still want
  to see all tags of a headline occasionally.

- {{{kbd(:)}}} (~org-agenda-set-tags~) ::

  #+kindex: :
  #+findex: org-agenda-set-tags
  Set tags for the current headline.  If there is an active region in
  the agenda, change a tag for all headings in the region.

- {{{kbd(\,)}}} (~org-agenda-priority~) ::

  #+kindex: ,
  #+findex: org-agenda-priority
  Set the priority for the current item.  Org mode prompts for the
  priority character.  If you reply with {{{kbd(SPC)}}}, the priority
  cookie is removed from the entry.

- {{{kbd(+)}}} or {{{kbd(S-UP)}}} (~org-agenda-priority-up~) ::

  #+kindex: +
  #+kindex: S-UP
  #+findex: org-agenda-priority-up
  Increase the priority of the current item.  The priority is changed
  in the original buffer, but the agenda is not resorted.  Use the
  {{{kbd(r)}}} key for this.

- {{{kbd(-)}}} or {{{kbd(S-DOWN)}}} (~org-agenda-priority-down~) ::

  #+kindex: -
  #+kindex: S-DOWN
  #+findex: org-agenda-priority-down
  Decrease the priority of the current item.

- {{{kbd(C-c C-x e)}}} or short {{{kbd(e)}}} (~org-agenda-set-effort~) ::

  #+kindex: e
  #+kindex: C-c C-x e
  #+findex: org-agenda-set-effort
  Set the effort property for the current item.

- {{{kbd(C-c C-z)}}} or short {{{kbd(z)}}} (~org-agenda-add-note~) ::

  #+kindex: z
  #+kindex: C-c C-z
  #+findex: org-agenda-add-note
  #+vindex: org-log-into-drawer
  Add a note to the entry.  This note is recorded, and then filed to
  the same location where state change notes are put.  Depending on
  ~org-log-into-drawer~, this may be inside a drawer.

- {{{kbd(C-c C-a)}}} (~org-attach~) ::

  #+kindex: C-c C-a
  #+findex: org-attach
  Dispatcher for all command related to attachments.

- {{{kbd(C-c C-s)}}} (~org-agenda-schedule~) ::

  #+kindex: C-c C-s
  #+findex: org-agenda-schedule
  Schedule this item.  With a prefix argument, remove the
  scheduling timestamp

- {{{kbd(C-c C-d)}}} (~org-agenda-deadline~) ::

  #+kindex: C-c C-d
  #+findex: org-agenda-deadline
  Set a deadline for this item.  With a prefix argument, remove the
  deadline.

- {{{kbd(S-RIGHT)}}} (~org-agenda-do-date-later~) ::

  #+kindex: S-RIGHT
  #+findex: org-agenda-do-date-later
  Change the timestamp associated with the current line by one day
  into the future.  If the date is in the past, the first call to this
  command moves it to today.  With a numeric prefix argument, change
  it by that many days.  For example, {{{kbd(3 6 5 S-RIGHT)}}} changes
  it by a year.  With a {{{kbd(C-u)}}} prefix, change the time by one
  hour.  If you immediately repeat the command, it will continue to
  change hours even without the prefix argument.  With a double
  {{{kbd(C-u C-u)}}} prefix, do the same for changing minutes.  The
  stamp is changed in the original Org file, but the change is not
  directly reflected in the agenda buffer.  Use {{{kbd(r)}}} or
  {{{kbd(g)}}} to update the buffer.

- {{{kbd(S-LEFT)}}} (~org-agenda-do-date-earlier~) ::

  #+kindex: S-LEFT
  #+findex: org-agenda-do-date-earlier
  Change the timestamp associated with the current line by one day
  into the past.

- {{{kbd(>)}}} (~org-agenda-date-prompt~) ::

  #+kindex: >
  #+findex: org-agenda-date-prompt
  Change the timestamp associated with the current line.  The key
  {{{kbd(>)}}} has been chosen, because it is the same as
  {{{kbd(S-.)}}}  on my keyboard.

- {{{kbd(I)}}} (~org-agenda-clock-in~) ::

  #+kindex: I
  #+findex: org-agenda-clock-in
  Start the clock on the current item.  If a clock is running already,
  it is stopped first.

- {{{kbd(O)}}} (~org-agenda-clock-out~) ::

  #+kindex: O
  #+findex: org-agenda-clock-out
  Stop the previously started clock.

- {{{kbd(X)}}} (~org-agenda-clock-cancel~) ::

  #+kindex: X
  #+findex: org-agenda-clock-cancel
  Cancel the currently running clock.

- {{{kbd(J)}}} (~org-agenda-clock-goto~) ::

  #+kindex: J
  #+findex: org-agenda-clock-goto
  Jump to the running clock in another window.

- {{{kbd(k)}}} (~org-agenda-capture~) ::

  #+kindex: k
  #+findex: org-agenda-capture
  #+cindex: capturing, from agenda
  #+vindex: org-capture-use-agenda-date
  Like ~org-capture~, but use the date at point as the default date
  for the capture template.  See ~org-capture-use-agenda-date~ to make
  this the default behavior of ~org-capture~.

*** Bulk remote editing selected entries
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: remote editing, bulk, from agenda
#+vindex: org-agenda-bulk-custom-functions

- {{{kbd(m)}}} (~org-agenda-bulk-mark~) ::
  #+kindex: m
  #+findex: org-agenda-bulk-mark

  Mark the entry at point for bulk action.  If there is an active
  region in the agenda, mark the entries in the region.  With numeric
  prefix argument, mark that many successive entries.

- {{{kbd(*)}}} (~org-agenda-bulk-mark-all~) ::
  #+kindex: *
  #+findex: org-agenda-bulk-mark-all

  Mark all visible agenda entries for bulk action.

- {{{kbd(u)}}} (~org-agenda-bulk-unmark~) ::
  #+kindex: u
  #+findex: org-agenda-bulk-unmark

  Unmark entry for bulk action.

- {{{kbd(U)}}} (~org-agenda-bulk-unmark-all~) ::
  #+kindex: U
  #+findex: org-agenda-bulk-unmark-all

  Unmark all marked entries for bulk action.

- {{{kbd(M-m)}}} (~org-agenda-bulk-toggle~) ::
  #+kindex: M-m
  #+findex: org-agenda-bulk-toggle

  Toggle mark of the entry at point for bulk action.

- {{{kbd(M-*)}}} (~org-agenda-bulk-toggle-all~) ::
  #+kindex: M-*
  #+findex: org-agenda-bulk-toggle-all

  Toggle mark of every entry for bulk action.

- {{{kbd(%)}}} (~org-agenda-bulk-mark-regexp~) ::
  #+kindex: %
  #+findex: org-agenda-bulk-mark-regexp

  Mark entries matching a regular expression for bulk action.

- {{{kbd(B)}}} (~org-agenda-bulk-action~) ::
  #+kindex: B
  #+findex: org-agenda-bulk-action
  #+vindex: org-agenda-bulk-persistent-marks

  Bulk action: act on all marked entries in the agenda.  This prompts
  for another key to select the action to be applied.  The prefix
  argument to {{{kbd(B)}}} is passed through to the {{{kbd(s)}}} and
  {{{kbd(d)}}} commands, to bulk-remove these special timestamps.  By
  default, marks are removed after the bulk.  If you want them to
  persist, set ~org-agenda-bulk-persistent-marks~ to ~t~ or hit
  {{{kbd(p)}}} at the prompt.

  - {{{kbd(p)}}} ::

    Toggle persistent marks.

  - {{{kbd($)}}} ::

    Archive all selected entries.

  - {{{kbd(A)}}} ::

    Archive entries by moving them to their respective archive
    siblings.

  - {{{kbd(t)}}} ::

    Change TODO state.  This prompts for a single TODO keyword and
    changes the state of all selected entries, bypassing blocking and
    suppressing logging notes---but not timestamps.

  - {{{kbd(+)}}} ::

    Add a tag to all selected entries.

  - {{{kbd(-)}}} ::

    Remove a tag from all selected entries.

  - {{{kbd(s)}}} ::

    Schedule all items to a new date.  To shift existing schedule
    dates by a fixed number of days, use something starting with
    double plus at the prompt, for example =++8d= or =++2w=.

  - {{{kbd(d)}}} ::

    Set deadline to a specific date.

  - {{{kbd(r)}}} ::

    Prompt for a single refile target and move all entries.  The
    entries are no longer in the agenda; refresh ({{{kbd(g)}}}) to
    bring them back.

  - {{{kbd(S)}}} ::

    Reschedule randomly into the coming N days.  N is prompted for.
    With a prefix argument ({{{kbd(C-u B S)}}}), scatter only across
    weekdays.

  - {{{kbd(f)}}} ::

    #+vindex: org-agenda-bulk-custom-functions
    Apply a function[fn:: You can also create persistent custom
    functions through ~org-agenda-bulk-custom-functions~.] to marked
    entries.  For example, the function below sets the =CATEGORY=
    property of the entries to =web=.

    #+begin_src emacs-lisp
    (defun set-category ()
      (interactive "P")
      (let ((marker (or (org-get-at-bol 'org-hd-marker)
                        (org-agenda-error))))
        (org-with-point-at marker
          (org-back-to-heading t)
          (org-set-property "CATEGORY" "web"))))
    #+end_src

*** Calendar commands
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: calendar commands, from agenda

- {{{kbd(c)}}} (~org-agenda-goto-calendar~) ::

  #+kindex: c
  #+findex: org-agenda-goto-calendar
  Open the Emacs calendar and go to the date at point in the agenda.

- {{{kbd(c)}}} (~org-calendar-goto-agenda~) ::

  #+kindex: c
  #+findex: org-calendar-goto-agenda
  When in the calendar, compute and show the Org agenda for the date
  at point.

- {{{kbd(i)}}} (~org-agenda-diary-entry~) ::
  #+kindex: i
  #+findex: org-agenda-diary-entry

  #+cindex: diary entries, creating from agenda
  Insert a new entry into the diary, using the date at point and (for
  block entries) the date at the mark.  This adds to the Emacs diary
  file[fn:: This file is parsed for the agenda when
  ~org-agenda-include-diary~ is set.], in a way similar to the
  {{{kbd(i)}}} command in the calendar.  The diary file pops up in
  another window, where you can add the entry.

  #+vindex: org-agenda-diary-file
  If you configure ~org-agenda-diary-file~ to point to an Org file,
  Org creates entries in that file instead.  Most entries are stored
  in a date-based outline tree that will later make it easy to archive
  appointments from previous months/years.  The tree is built under an
  entry with a =DATE_TREE= property, or else with years as top-level
  entries.  Emacs prompts you for the entry text---if you specify it,
  the entry is created in ~org-agenda-diary-file~ without further
  interaction.  If you directly press {{{kbd(RET)}}} at the prompt
  without typing text, the target file is shown in another window for
  you to finish the entry there.  See also the {{{kbd(k r)}}} command.

- {{{kbd(M)}}} (~org-agenda-phases-of-moon~) ::

  #+kindex: M
  #+findex: org-agenda-phases-of-moon
  Show the phases of the moon for the three months around current
  date.

- {{{kbd(S)}}} (~org-agenda-sunrise-sunset~) ::

  #+kindex: S
  #+findex: org-agenda-sunrise-sunset
  Show sunrise and sunset times.  The geographical location must be
  set with calendar variables, see the documentation for the Emacs
  calendar.

- {{{kbd(C)}}} (~org-agenda-convert-date~) ::

  #+kindex: C
  #+findex: org-agenda-convert-date
  Convert the date at point into many other cultural and historic
  calendars.

- {{{kbd(H)}}} (~org-agenda-holidays~) ::

  #+kindex: H
  #+findex: org-agenda-holidays
  Show holidays for three months around point date.

*** Quit and exit
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- {{{kbd(q)}}} (~org-agenda-quit~) ::
  #+kindex: q
  #+findex: org-agenda-quit

  Quit agenda, remove the agenda buffer.

- {{{kbd(x)}}} (~org-agenda-exit~) ::
  #+kindex: x
  #+findex: org-agenda-exit

  #+cindex: agenda files, removing buffers
  Exit agenda, remove the agenda buffer and all buffers loaded by
  Emacs for the compilation of the agenda.  Buffers created by the
  user to visit Org files are not removed.

** Custom Agenda Views
:PROPERTIES:
:DESCRIPTION: Defining special searches and views.
:END:
#+cindex: custom agenda views
#+cindex: agenda views, custom

Custom agenda commands serve two purposes: to store and quickly access
frequently used TODO and tags searches, and to create special
composite agenda buffers.  Custom agenda commands are accessible
through the dispatcher (see [[*The Agenda Dispatcher]]), just like the
default commands.

*** Storing searches
:PROPERTIES:
:DESCRIPTION: Type once, use often.
:END:

The first application of custom searches is the definition of keyboard
shortcuts for frequently used searches, either creating an agenda
buffer, or a sparse tree (the latter covering of course only the
current buffer).

#+kindex: C @r{(Agenda dispatcher)}
#+vindex: org-agenda-custom-commands
#+cindex: agenda views, main example
#+cindex: agenda, as an agenda views
#+cindex: agenda*, as an agenda views
#+cindex: tags, as an agenda view
#+cindex: todo, as an agenda view
#+cindex: tags-todo
#+cindex: todo-tree
#+cindex: occur-tree
#+cindex: tags-tree
Custom commands are configured in the variable
~org-agenda-custom-commands~.  You can customize this variable, for
example by pressing {{{kbd(C)}}} from the agenda dispatcher (see [[*The
Agenda Dispatcher]]).  You can also directly set it with Emacs Lisp in
the Emacs init file.  The following example contains all valid agenda
views:

#+begin_src emacs-lisp
(setq org-agenda-custom-commands
      '(("x" agenda)
        ("y" agenda*)
        ("w" todo "WAITING")
        ("W" todo-tree "WAITING")
        ("u" tags "+boss-urgent")
        ("v" tags-todo "+boss-urgent")
        ("U" tags-tree "+boss-urgent")
        ("f" occur-tree "\\<FIXME\\>")
        ("h" . "HOME+Name tags searches") ;description for "h" prefix
        ("hl" tags "+home+Lisa")
        ("hp" tags "+home+Peter")
        ("hk" tags "+home+Kim")))
#+end_src

The initial string in each entry defines the keys you have to press
after the dispatcher command in order to access the command.  Usually
this is just a single character, but if you have many similar
commands, you can also define two-letter combinations where the first
character is the same in several combinations and serves as a prefix
key[fn:: You can provide a description for a prefix key by inserting a
cons cell with the prefix and the description.].  The second parameter
is the search type, followed by the string or regular expression to be
used for the matching.  The example above will therefore define:

- {{{kbd(x)}}} ::

  as a global search for agenda entries planned[fn:34] this week/day.

- {{{kbd(y)}}} ::

  as the same search, but only for entries with an hour specification
  like =[h]h:mm=---think of them as appointments.

- {{{kbd(w)}}} ::

  as a global search for TODO entries with =WAITING= as the TODO
  keyword.

- {{{kbd(W)}}} ::

  as the same search, but only in the current buffer and displaying
  the results as a sparse tree.

- {{{kbd(u)}}} ::

  as a global tags search for headlines tagged =boss= but not
  =urgent=.

- {{{kbd(v)}}} ::

  The same search, but limiting it to headlines that are also TODO
  items.

- {{{kbd(U)}}} ::

  as the same search, but only in the current buffer and displaying
  the result as a sparse tree.

- {{{kbd(f)}}} ::

  to create a sparse tree (again, current buffer only) with all
  entries containing the word =FIXME=.

- {{{kbd(h)}}} ::

  as a prefix command for a =HOME= tags search where you have to press
  an additional key ({{{kbd(l)}}}, {{{kbd(p)}}} or {{{kbd(k)}}}) to
  select a name (Lisa, Peter, or Kim) as additional tag to match.

Note that ~*-tree~ agenda views need to be called from an Org buffer
as they operate on the current buffer only.

*** Block agenda
:PROPERTIES:
:DESCRIPTION: All the stuff you need in a single buffer.
:END:
#+cindex: block agenda
#+cindex: agenda, with block views

Another possibility is the construction of agenda views that comprise
the results of /several/ commands, each of which creates a block in
the agenda buffer.  The available commands include ~agenda~ for the
daily or weekly agenda (as created with {{{kbd(a)}}}) , ~alltodo~ for
the global TODO list (as constructed with {{{kbd(t)}}}), ~stuck~ for
the list of stuck projects (as obtained with {{{kbd(#)}}}) and the
matching commands discussed above: ~todo~, ~tags~, and ~tags-todo~.

Here are two examples:

#+begin_src emacs-lisp
(setq org-agenda-custom-commands
      '(("h" "Agenda and Home-related tasks"
         ((agenda "")
          (tags-todo "home")
          (tags "garden")))
        ("o" "Agenda and Office-related tasks"
         ((agenda "")
          (tags-todo "work")
          (tags "office")))))
#+end_src

#+texinfo: @noindent
This defines {{{kbd(h)}}} to create a multi-block view for stuff you
need to attend to at home.  The resulting agenda buffer contains your
agenda for the current week, all TODO items that carry the tag =home=,
and also all lines tagged with =garden=.  Finally the command
{{{kbd(o)}}} provides a similar view for office tasks.

*** Setting options for custom commands
:PROPERTIES:
:DESCRIPTION: Changing the rules.
:ALT_TITLE: Setting options
:END:
#+cindex: options, for custom agenda views

#+vindex: org-agenda-custom-commands
Org mode contains a number of variables regulating agenda construction
and display.  The global variables define the behavior for all agenda
commands, including the custom commands.  However, if you want to
change some settings just for a single custom view, you can do so.
Setting options requires inserting a list of variable names and values
at the right spot in ~org-agenda-custom-commands~.  For example:

#+begin_src emacs-lisp
(setq org-agenda-custom-commands
      '(("w" todo "WAITING"
         ((org-agenda-sorting-strategy '(priority-down))
          (org-agenda-prefix-format "  Mixed: ")))
        ("U" tags-tree "+boss-urgent"
         ((org-show-context-detail 'minimal)))
        ("N" search ""
         ((org-agenda-files '("~org/notes.org"))
          (org-agenda-text-search-extra-files nil)))))
#+end_src

#+texinfo: @noindent
Now the {{{kbd(w)}}} command sorts the collected entries only by
priority, and the prefix format is modified to just say =Mixed:=
instead of giving the category of the entry.  The sparse tags tree of
{{{kbd(U)}}} now turns out ultra-compact, because neither the headline
hierarchy above the match, nor the headline following the match are
shown.  The command {{{kbd(N)}}} does a text search limited to only
a single file.

For command sets creating a block agenda, ~org-agenda-custom-commands~
has two separate spots for setting options.  You can add options that
should be valid for just a single command in the set, and options that
should be valid for all commands in the set.  The former are just
added to the command entry; the latter must come after the list of
command entries.  Going back to the block agenda example (see [[*Block
agenda]]), let's change the sorting strategy for the {{{kbd(h)}}}
commands to ~priority-down~, but let's sort the results for =garden=
tags query in the opposite order, ~priority-up~.  This would look like
this:

#+begin_src emacs-lisp
(setq org-agenda-custom-commands
      '(("h" "Agenda and Home-related tasks"
         ((agenda)
          (tags-todo "home")
          (tags "garden"
                ((org-agenda-sorting-strategy '(priority-up)))))
         ((org-agenda-sorting-strategy '(priority-down))))
        ("o" "Agenda and Office-related tasks"
         ((agenda)
          (tags-todo "work")
          (tags "office")))))
#+end_src

As you see, the values and parentheses setting is a little complex.
When in doubt, use the customize interface to set this variable---it
fully supports its structure.  Just one caveat: when setting options
in this interface, the /values/ are just Lisp expressions.  So if the
value is a string, you need to add the double-quotes around the value
yourself.

#+vindex: org-agenda-custom-commands-contexts
To control whether an agenda command should be accessible from
a specific context, you can customize
~org-agenda-custom-commands-contexts~.  Let's say for example that you
have an agenda command {{{kbd(o)}}} displaying a view that you only
need when reading emails.  Then you would configure this option like
this:

#+begin_src emacs-lisp
(setq org-agenda-custom-commands-contexts
      '(("o" (in-mode . "message-mode"))))
#+end_src

You can also tell that the command key {{{kbd(o)}}} should refer to
another command key {{{kbd(r)}}}.  In that case, add this command key
like this:

#+begin_src emacs-lisp
(setq org-agenda-custom-commands-contexts
      '(("o" "r" (in-mode . "message-mode"))))
#+end_src

See the docstring of the variable for more information.

** Exporting Agenda Views
:PROPERTIES:
:DESCRIPTION: Writing a view to a file.
:END:
#+cindex: agenda views, exporting

If you are away from your computer, it can be very useful to have a
printed version of some agenda views to carry around.  Org mode can
export custom agenda views as plain text, HTML[fn:: For HTML you need
to install Hrvoje Nikšić's =htmlize.el= as an Emacs package from
[[https://elpa.nongnu.org/][NonGNU ELPA]] or from
[[https://github.com/hniksic/emacs-htmlize][Hrvoje Nikšić's repository]].],
Postscript, PDF[fn:35], and iCalendar files.  If you
want to do this only occasionally, use the following command:

- {{{kbd(C-x C-w)}}} (~org-agenda-write~) ::
  #+kindex: C-x C-w
  #+findex: org-agenda-write
  #+cindex: exporting agenda views
  #+cindex: agenda views, exporting

  #+vindex: org-agenda-exporter-settings
  Write the agenda view to a file.

If you need to export certain agenda views frequently, you can
associate any custom agenda command with a list of output file
names[fn:: If you want to store standard views like the weekly agenda
or the global TODO list as well, you need to define custom commands
for them in order to be able to specify file names.].  Here is an
example that first defines custom commands for the agenda and the
global TODO list, together with a number of files to which to export
them.  Then we define two block agenda commands and specify file names
for them as well.  File names can be relative to the current working
directory, or absolute.

#+begin_src emacs-lisp
(setq org-agenda-custom-commands
      '(("X" agenda "" nil ("agenda.html" "agenda.ps"))
        ("Y" alltodo "" nil ("todo.html" "todo.txt" "todo.ps"))
        ("h" "Agenda and Home-related tasks"
         ((agenda "")
          (tags-todo "home")
          (tags "garden"))
         nil
         ("~/views/home.html"))
        ("o" "Agenda and Office-related tasks"
         ((agenda)
          (tags-todo "work")
          (tags "office"))
         nil
         ("~/views/office.ps" "~/calendars/office.ics"))))
#+end_src

The extension of the file name determines the type of export.  If it
is =.html=, Org mode uses the htmlize package to convert the buffer to
HTML and save it to this file name.  If the extension is =.ps=,
~ps-print-buffer-with-faces~ is used to produce Postscript output.  If
the extension is =.ics=, iCalendar export is run export over all files
that were used to construct the agenda, and limit the export to
entries listed in the agenda.  Any other extension produces a plain
ASCII file.

The export files are /not/ created when you use one of those
commands interactively because this might use too much overhead.
Instead, there is a special command to produce /all/ specified
files in one step:

- {{{kbd(e)}}} (~org-store-agenda-views~) ::

  #+kindex: e @r{(Agenda dispatcher)}
  #+findex: org-store-agenda-views
  Export all agenda views that have export file names associated with
  them.

You can use the options section of the custom agenda commands to also
set options for the export commands.  For example:

#+begin_src emacs-lisp
(setq org-agenda-custom-commands
      '(("X" agenda ""
         ((ps-number-of-columns 2)
          (ps-landscape-mode t)
          (org-agenda-prefix-format " [ ] ")
          (org-agenda-with-colors nil)
          (org-agenda-remove-tags t))
         ("theagenda.ps"))))
#+end_src

#+texinfo: @noindent
#+vindex: org-agenda-exporter-settings
This command sets two options for the Postscript exporter, to make it
print in two columns in landscape format---the resulting page can be
cut in two and then used in a paper agenda.  The remaining settings
modify the agenda prefix to omit category and scheduling information,
and instead include a checkbox to check off items.  We also remove the
tags to make the lines compact, and we do not want to use colors for
the black-and-white printer.  Settings specified in
~org-agenda-exporter-settings~ also apply, e.g.,

#+begin_src emacs-lisp
(setq org-agenda-exporter-settings
      '((ps-number-of-columns 2)
        (ps-landscape-mode t)
        (org-agenda-add-entry-text-maxlines 5)
        (htmlize-output-type 'css)))
#+end_src

#+texinfo: @noindent
but the settings in ~org-agenda-custom-commands~ take precedence.

From the command line you may also use:

#+begin_src shell
emacs -eval (org-batch-store-agenda-views) -kill
#+end_src

#+texinfo: @noindent
or, if you need to modify some parameters[fn:: Quoting depends on the
system you use, please check the FAQ for examples.]

#+begin_src shell
emacs -eval '(org-batch-store-agenda-views                      \
              org-agenda-span (quote month)                     \
              org-agenda-start-day "2007-11-01"                 \
              org-agenda-include-diary nil                      \
              org-agenda-files (quote ("~/org/project.org")))'  \
      -kill
#+end_src

#+texinfo: @noindent
which creates the agenda views restricted to the file
=~/org/project.org=, without diary entries and with a 30-day extent.

You can also extract agenda information in a way that allows further
processing by other programs.  See [[*Extracting Agenda Information]], for
more information.

** Using Column View in the Agenda
:PROPERTIES:
:DESCRIPTION: Using column view for collected entries.
:ALT_TITLE: Agenda Column View
:END:
#+cindex: column view, in agenda
#+cindex: agenda, column view

Column view (see [[*Column View]]) is normally used to view and edit
properties embedded in the hierarchical structure of an Org file.  It
can be quite useful to use column view also from the agenda, where
entries are collected by certain criteria.

- {{{kbd(C-c C-x C-c)}}} (~org-agenda-columns~) ::
  #+kindex: C-c C-x C-c
  #+findex: org-agenda-columns

  Turn on column view in the agenda.

To understand how to use this properly, it is important to realize
that the entries in the agenda are no longer in their proper outline
environment.  This causes the following issues:

1.
   #+vindex: org-columns-default-format-for-agenda
   #+vindex: org-columns-default-format
   Org needs to make a decision which columns format to use.  Since
   the entries in the agenda are collected from different files, and
   different files may have different columns formats, this is a
   non-trivial problem.  Org first checks if
   ~org-overriding-columns-format~ is currently set, and if so, takes
   the format from there.  You should set this variable only in the
   /local settings section/ of a custom agenda command (see [[*Custom
   Agenda Views]]) to make it valid for that specific agenda view.  If
   no such binding exists, it checks, in sequence,
   ~org-columns-default-format-for-agenda~, the format associated with
   the first item in the agenda (through a property or a =#+COLUMNS=
   setting in that buffer) and finally ~org-columns-default-format~.

2.
   #+cindex: @samp{CLOCKSUM}, special property
   If any of the columns has a summary type defined (see [[*Column
   attributes]]), turning on column view in the agenda visits all
   relevant agenda files and make sure that the computations of this
   property are up to date.  This is also true for the special
   =CLOCKSUM= property.  Org then sums the values displayed in the
   agenda.  In the daily/weekly agenda, the sums cover a single day;
   in all other views they cover the entire block.

   It is important to realize that the agenda may show the same entry
   /twice/---for example as scheduled and as a deadline---and it may
   show two entries from the same hierarchy (for example a /parent/
   and its /child/).  In these cases, the summation in the agenda
   leads to incorrect results because some values count double.

3. When the column view in the agenda shows the =CLOCKSUM= property,
   that is always the entire clocked time for this item.  So even in
   the daily/weekly agenda, the clocksum listed in column view may
   originate from times outside the current view.  This has the
   advantage that you can compare these values with a column listing
   the planned total effort for a task---one of the major
   applications for column view in the agenda.  If you want
   information about clocked time in the displayed period use clock
   table mode (press {{{kbd(R)}}} in the agenda).

4.
   #+cindex: @samp{CLOCKSUM_T}, special property
   When the column view in the agenda shows the =CLOCKSUM_T= property,
   that is always today's clocked time for this item.  So even in the
   weekly agenda, the clocksum listed in column view only originates
   from today.  This lets you compare the time you spent on a task for
   today, with the time already spent---via =CLOCKSUM=---and with
   the planned total effort for it.

* Markup for Rich Contents
:PROPERTIES:
:DESCRIPTION: Compose beautiful documents.
:END:

Org is primarily about organizing and searching through your
plain-text notes.  However, it also provides a lightweight yet robust
markup language for rich text formatting and more.  For instance, you
may want to center or emphasize text.  Or you may need to insert
a formula or image in your writing.  Org offers syntax for all of this
and more.  Used in conjunction with the export framework (see
[[*Exporting]]), you can author beautiful documents in Org---like the fine
manual you are currently reading.

** Paragraphs
:PROPERTIES:
:DESCRIPTION: The basic unit of text.
:END:

#+cindex: paragraphs, markup rules
Paragraphs are separated by at least one empty line.  If you need to
enforce a line break within a paragraph, use =\\= at the end of
a line.

#+cindex: line breaks, markup rules
To preserve the line breaks, indentation and blank lines in a region,
but otherwise use normal formatting, you can use this construct, which
can also be used to format poetry.

#+cindex: @samp{BEGIN_VERSE}
#+cindex: verse blocks
#+begin_example
,#+BEGIN_VERSE
 Great clouds overhead
 Tiny black birds rise and fall
 Snow covers Emacs

    ---AlexSchroeder
,#+END_VERSE
#+end_example

When quoting a passage from another document, it is customary to
format this as a paragraph that is indented on both the left and the
right margin.  You can include quotations in Org documents like this:

#+cindex: @samp{BEGIN_QUOTE}
#+cindex: quote blocks
#+begin_example
,#+BEGIN_QUOTE
Everything should be made as simple as possible,
but not any simpler ---Albert Einstein
,#+END_QUOTE
#+end_example

If you would like to center some text, do it like this:

#+cindex: @samp{BEGIN_CENTER}
#+cindex: center blocks
#+begin_example
,#+BEGIN_CENTER
Everything should be made as simple as possible, \\
but not any simpler
,#+END_CENTER
#+end_example

** Emphasis and Monospace
:PROPERTIES:
:DESCRIPTION: Bold, italic, etc.
:END:
#+cindex: underlined text, markup rules
#+cindex: bold text, markup rules
#+cindex: italic text, markup rules
#+cindex: verbatim text, markup rules
#+cindex: code text, markup rules
#+cindex: strike-through text, markup rules

You can make words =*bold*=, =/italic/=, =_underlined_=, ==verbatim==
and =~code~=, and, if you must, =+strike-through+=.  Text in the code
and verbatim string is not processed for Org specific syntax; it is
exported verbatim.

#+vindex: org-fontify-emphasized-text
To turn off fontification for marked up text, you can set
~org-fontify-emphasized-text~ to ~nil~.  To narrow down the list of
available markup syntax, you can customize ~org-emphasis-alist~.

Sometimes, when marked text also contains the marker character itself,
the result may be unsettling.  For example,

#+begin_example
/One may expect this whole sentence to be italicized, but the
following ~user/?variable~ contains =/= character, which effectively
stops emphasis there./
#+end_example

You can use zero width space to help Org sorting out the ambiguity.
See [[*Escape Character]] for more details.

** Subscripts and Superscripts
:PROPERTIES:
:DESCRIPTION: Simple syntax for raising/lowering text.
:END:
#+cindex: subscript
#+cindex: superscript

=^= and =_= are used to indicate super- and subscripts.  To increase
the readability of ASCII text, it is not necessary, but OK, to
surround multi-character sub- and superscripts with curly braces.  For
example

#+begin_example
The radius of the sun is R_sun = 6.96 x 10^8 m.  On the other hand,
the radius of Alpha Centauri is R_{Alpha Centauri} = 1.28 x R_{sun}.
#+end_example

#+vindex: org-use-sub-superscripts
If you write a text where the underscore is often used in a different
context, Org's convention to always interpret these as subscripts can
get in your way.  Configure the variable ~org-use-sub-superscripts~ to
change this convention.  For example, when setting this variable to
~{}~, =a_b= is not interpreted as a subscript, but =a_{b}= is.

You can set ~org-use-sub-superscripts~ in a file using the export
option =^:= (see [[*Export Settings][Export Settings]]).  For example, =#+OPTIONS: ^:{}=
sets ~org-use-sub-superscripts~ to ~{}~ and limits super- and
subscripts to the curly bracket notation.

You can also toggle the visual display of super- and subscripts:

- {{{kbd(C-c C-x \)}}} (~org-toggle-pretty-entities~) ::

  #+kindex: C-c C-x \
  #+findex: org-toggle-pretty-entities
  This command formats sub- and superscripts in a WYSIWYM way.

#+vindex: org-pretty-entities
#+vindex: org-pretty-entities-include-sub-superscripts
Set both ~org-pretty-entities~ and
~org-pretty-entities-include-sub-superscripts~ to ~t~ to start with
super- and subscripts /visually/ interpreted as specified by the
option ~org-use-sub-superscripts~.

** Special Symbols
:PROPERTIES:
:DESCRIPTION: Greek letters and other symbols.
:END:
#+cindex: math symbols
#+cindex: special symbols
#+cindex: entities

You can use LaTeX-like syntax to insert special symbols---named
entities---like =\alpha= to indicate the Greek letter, or =\to= to indicate
an arrow.  Completion for these symbols is available, just type =\=
and maybe a few letters, and press {{{kbd(M-TAB)}}} to see possible
completions.  If you need such a symbol inside a word, terminate it
with a pair of curly brackets.  For example

#+begin_example
Pro tip: Given a circle \Gamma of diameter d, the length of its
circumference is \pi{}d.
#+end_example

#+findex: org-entities-help
#+vindex: org-entities-user
A large number of entities is provided, with names taken from both
HTML and LaTeX; you can comfortably browse the complete list from
a dedicated buffer using the command ~org-entities-help~.  It is also
possible to provide your own special symbols in the variable
~org-entities-user~.

During export, these symbols are transformed into the native format of
the exporter back-end.  Strings like =\alpha= are exported as =&alpha;= in
the HTML output, and as =\(\alpha\)= in the LaTeX output.  Similarly, =\nbsp=
becomes =&nbsp;= in HTML and =~= in LaTeX.

#+cindex: special symbols, in-buffer display
If you would like to see entities displayed as UTF-8 characters, use
the following command[fn:: You can turn this on by default by setting
the variable ~org-pretty-entities~, or on a per-file base with the
=STARTUP= option =entitiespretty=.]:

- {{{kbd(C-c C-x \)}}} (~org-toggle-pretty-entities~) ::
  #+kindex: C-c C-x \
  #+findex: org-toggle-pretty-entities

  Toggle display of entities as UTF-8 characters.  This does not
  change the buffer content which remains plain ASCII, but it overlays
  the UTF-8 character for display purposes only.

#+cindex: shy hyphen, special symbol
#+cindex: dash, special symbol
#+cindex: ellipsis, special symbol
In addition to regular entities defined above, Org exports in a
special way[fn:: This behavior can be disabled with =-= export setting
(see [[*Export Settings]]).] the following commonly used character
combinations: =\-= is treated as a shy hyphen, =--= and =---= are
converted into dashes, and =...= becomes a compact set of dots.

** Embedded LaTeX
:PROPERTIES:
:DESCRIPTION: LaTeX can be freely used inside Org documents.
:END:
#+cindex: @TeX{} interpretation
#+cindex: @LaTeX{} interpretation

Plain ASCII is normally sufficient for almost all note taking.
Exceptions include scientific notes, which often require mathematical
symbols and the occasional formula.  LaTeX[fn:36] is widely used to
typeset scientific documents.  Org mode supports embedding LaTeX code
into its files, because many academics are used to writing and reading
LaTeX source code, and because it can be readily processed to produce
pretty output for a number of export back-ends.

*** LaTeX fragments
:PROPERTIES:
:DESCRIPTION: Complex formulas made easy.
:END:
#+cindex: @LaTeX{} fragments

#+vindex: org-format-latex-header
Org mode can contain LaTeX math fragments, and it supports ways to
process these for several export back-ends.  When exporting to LaTeX,
the code is left as it is.  When exporting to HTML, Org can use either
[[https://www.mathjax.org][MathJax]] (see [[*Math formatting in HTML export]]) or transcode the math
into images (see [[*Previewing LaTeX fragments]]).

LaTeX fragments do not need any special marking at all.  The following
snippets are identified as LaTeX source code:

- Environments of any kind[fn:37].  The only requirement is that the
  =\begin= statement appears on a new line, preceded by only
  whitespace.

- Text within the usual LaTeX math delimiters.  To avoid conflicts
  with currency specifications, single =$= characters are only
  recognized as math delimiters if the enclosed text contains at most
  two line breaks, is directly attached to the =$= characters with no
  whitespace in between, and if the closing =$= is followed by
  whitespace, punctuation or a dash.  For the other delimiters, there
  is no such restriction, so when in doubt, use =\(...\)= as inline
  math delimiters.

#+texinfo: @noindent
For example:

#+begin_example
\begin{equation}                        % arbitrary environments,
x=\sqrt{b}                              % even tables, figures
\end{equation}                          % etc

If $a^2=b$ and \( b=2 \), then the solution must be
either $$ a=+\sqrt{2} $$ or \[ a=-\sqrt{2} \].
#+end_example

#+vindex: org-export-with-latex
LaTeX processing can be configured with the variable
~org-export-with-latex~.  The default setting is ~t~ which means
MathJax for HTML, and no processing for ASCII and LaTeX back-ends.
You can also set this variable on a per-file basis using one of these
lines:

| =#+OPTIONS: tex:t=        | Do the right thing automatically (MathJax) |
| =#+OPTIONS: tex:nil=      | Do not process LaTeX fragments at all      |
| =#+OPTIONS: tex:verbatim= | Verbatim export, for jsMath or so          |

*** Previewing LaTeX fragments
:PROPERTIES:
:DESCRIPTION: What will this snippet look like?
:END:
#+cindex: @LaTeX{} fragments, preview

#+vindex: org-preview-latex-default-process
If you have a working LaTeX installation and =dvipng=, =dvisvgm= or
=convert= installed[fn:38], LaTeX fragments can be processed to
produce images of the typeset expressions to be used for inclusion
while exporting to HTML (see [[*LaTeX fragments]]), or for inline
previewing within Org mode.

#+vindex: org-format-latex-options
#+vindex: org-format-latex-header
You can customize the variables ~org-format-latex-options~ and
~org-format-latex-header~ to influence some aspects of the preview.
In particular, the ~:scale~ (and for HTML export, ~:html-scale~)
property of the former can be used to adjust the size of the preview
images.

- {{{kbd(C-c C-x C-l)}}} (~org-latex-preview~) ::
  #+kindex: C-c C-x C-l
  #+findex: org-latex-preview

  Produce a preview image of the LaTeX fragment at point and overlay
  it over the source code.  If there is no fragment at point, process
  all fragments in the current entry---between two headlines.

  When called with a single prefix argument, clear all images in the
  current entry.  Two prefix arguments produce a preview image for all
  fragments in the buffer, while three of them clear all the images in
  that buffer.

#+vindex: org-startup-with-latex-preview
You can turn on the previewing of all LaTeX fragments in a file with

: #+STARTUP: latexpreview

To disable it, simply use

: #+STARTUP: nolatexpreview

*** Using CDLaTeX to enter math
:PROPERTIES:
:DESCRIPTION: Speed up entering of formulas.
:ALT_TITLE: CDLaTeX mode
:END:
#+cindex: CD@LaTeX{}

CDLaTeX mode is a minor mode that is normally used in combination with
a major LaTeX mode like AUCTeX in order to speed-up insertion of
environments and math templates.  Inside Org mode, you can make use of
some of the features of CDLaTeX mode.  You need to install
=cdlatex.el= and =texmathp.el= (the latter comes also with AUCTeX)
from [[https://elpa.nongnu.org/][NonGNU ELPA]] with the [[https://www.gnu.org/software/emacs/manual/html_node/emacs/Package-Installation.html][Emacs packaging system]] or alternatively from
[[https://staff.fnwi.uva.nl/c.dominik/Tools/cdlatex/]].  Do not use
CDLaTeX mode itself under Org mode, but use the special version Org
CDLaTeX minor mode that comes as part of Org.  Turn it on for the
current buffer with {{{kbd(M-x org-cdlatex-mode)}}}, or for all Org
files with

#+begin_src emacs-lisp
(add-hook 'org-mode-hook #'turn-on-org-cdlatex)
#+end_src

When this mode is enabled, the following features are present (for
more details see the documentation of CDLaTeX mode):

#+attr_texinfo: :sep ,
- {{{kbd(C-c {)}}} ::
  #+kindex: C-c @{

  Insert an environment template.

- {{{kbd(TAB)}}} ::
  #+kindex: TAB

  The {{{kbd(TAB)}}} key expands the template if point is inside a
  LaTeX fragment[fn:: Org mode has a method to test if point is inside
  such a fragment, see the documentation of the function
  ~org-inside-LaTeX-fragment-p~.].  For example, {{{kbd(TAB)}}}
  expands =fr= to =\frac{}{}= and position point correctly inside the
  first brace.  Another {{{kbd(TAB)}}} gets you into the second brace.

  Even outside fragments, {{{kbd(TAB)}}} expands environment
  abbreviations at the beginning of a line.  For example, if you write
  =equ= at the beginning of a line and press {{{kbd(TAB)}}}, this
  abbreviation is expanded to an =equation= environment.  To get
  a list of all abbreviations, type {{{kbd(M-x
  cdlatex-command-help)}}}.

- {{{kbd(^)}}}, {{{kbd(_)}}} ::
  #+kindex: _
  #+kindex: ^
  #+vindex: cdlatex-simplify-sub-super-scripts

  Pressing {{{kbd(_)}}} and {{{kbd(^)}}} inside a LaTeX fragment
  inserts these characters together with a pair of braces.  If you use
  {{{kbd(TAB)}}} to move out of the braces, and if the braces surround
  only a single character or macro, they are removed again (depending
  on the variable ~cdlatex-simplify-sub-super-scripts~).

- {{{kbd(`)}}} ::
  #+kindex: `

  Pressing the backquote followed by a character inserts math macros,
  also outside LaTeX fragments.  If you wait more than 1.5 seconds
  after the backquote, a help window pops up.

- {{{kbd(')}}} ::
  #+kindex: '

  Pressing the single-quote followed by another character modifies the
  LaTeX symbol before point with an accent or a font.  If you wait
  more than 1.5 seconds after the single-quote, a help window pops up.
  Character modification works only inside LaTeX fragments; outside
  the quote is normal.

** Literal Examples
:PROPERTIES:
:DESCRIPTION: Source code examples with special formatting.
:END:
#+cindex: literal examples, markup rules
#+cindex: code line references, markup rules

You can include literal examples that should not be subjected to
markup.  Such examples are typeset in monospace, so this is well
suited for source code and similar examples.

#+cindex: @samp{BEGIN_EXAMPLE}
#+cindex: example block
#+begin_example
,#+BEGIN_EXAMPLE
  Some example from a text file.
,#+END_EXAMPLE
#+end_example

#+cindex: comma escape, in literal examples
There is one limitation, however.  You must insert a comma right
before lines starting with either =*=, =,*=, =#+= or =,#+=, as those
may be interpreted as outlines nodes or some other special syntax.
Org transparently strips these additional commas whenever it accesses
the contents of the block.

#+begin_example
,#+BEGIN_EXAMPLE
,,* I am no real headline
,#+END_EXAMPLE
#+end_example

For simplicity when using small examples, you can also start the
example lines with a colon followed by a space.  There may also be
additional whitespace before the colon:

#+begin_example
Here is an example
   : Some example from a text file.
#+end_example

#+cindex: formatting source code, markup rules
#+vindex: org-latex-src-block-backend
If the example is source code from a programming language, or any
other text that can be marked up by Font Lock in Emacs, you can ask
for the example to look like the fontified Emacs buffer[fn:39].  This
is done with the code block, where you also need to specify the name
of the major mode that should be used to fontify the example[fn:40],
see [[*Structure Templates]] for shortcuts to easily insert code blocks.

#+cindex: @samp{BEGIN_SRC}
#+cindex: source block
#+begin_example
,#+BEGIN_SRC emacs-lisp
  (defun org-xor (a b)
    "Exclusive or."
    (if a (not b) b))
 ,#+END_SRC
#+end_example

Both in =example= and in =src= snippets, you can add a =-n= switch to
the end of the =#+BEGIN= line, to get the lines of the example
numbered.  The =-n= takes an optional numeric argument specifying the
starting line number of the block.  If you use a =+n= switch, the
numbering from the previous numbered snippet is continued in the
current one.  The =+n= switch can also take a numeric argument.  This
adds the value of the argument to the last line of the previous block
to determine the starting line number.

#+begin_example
,#+BEGIN_SRC emacs-lisp -n 20
  ;; This exports with line number 20.
  (message "This is line 21")
,#+END_SRC

,#+BEGIN_SRC emacs-lisp +n 10
  ;; This is listed as line 31.
  (message "This is line 32")
,#+END_SRC
#+end_example

In literal examples, Org interprets strings like =(ref:name)= as
labels, and use them as targets for special hyperlinks like
=[[(name)]]=---i.e., the reference name enclosed in single parenthesis.
In HTML, hovering the mouse over such a link remote-highlights the
corresponding code line, which is kind of cool.

You can also add a =-r= switch which /removes/ the labels from the
source code[fn:: Adding =-k= to =-n -r= /keeps/ the labels in the
source code while using line numbers for the links, which might be
useful to explain those in an Org mode example code.].  With the =-n=
switch, links to these references are labeled by the line numbers from
the code listing.  Otherwise links use the labels with no parentheses.
Here is an example:

#+begin_example -l "(dumb-reference:%s)"
,#+BEGIN_SRC emacs-lisp -n -r
  (save-excursion                 (ref:sc)
     (goto-char (point-min))      (ref:jump)
,#+END_SRC
In line [[(sc)]] we remember the current position. [[(jump)][Line (jump)]]
jumps to point-min.
#+end_example

#+cindex: indentation, in source blocks
Source code and examples may be /indented/ in order to align nicely
with the surrounding text, and in particular with plain list structure
(see [[*Plain Lists]]).  By default, Org only retains the relative
indentation between lines, e.g., when exporting the contents of the
block.  However, you can use the =-i= switch to also preserve the
global indentation, if it does matter.  See [[*Editing Source Code]].

#+vindex: org-coderef-label-format
If the syntax for the label format conflicts with the language syntax,
use a =-l= switch to change the format, for example

: #+BEGIN_SRC pascal -n -r -l "((%s))"

#+texinfo: @noindent
See also the variable ~org-coderef-label-format~.

HTML export also allows examples to be published as text areas (see
[[*Text areas in HTML export]]).

Because the =#+BEGIN= ... =#+END= patterns need to be added so often,
a shortcut is provided (see [[*Structure Templates]]).

- {{{kbd(C-c ')}}} (~org-edit-special~) ::

  #+kindex: C-c '
  #+findex: org-edit-special
  Edit the source code example at point in its native mode.  This
  works by switching to a temporary buffer with the source code.  You
  need to exit by pressing {{{kbd(C-c ')}}} again.  The edited version
  then replaces the old version in the Org buffer.  Fixed-width
  regions---where each line starts with a colon followed by a
  space---are edited using Artist mode[fn:: You may select a different
  mode with the variable ~org-edit-fixed-width-region-mode~.] to allow
  creating ASCII drawings easily.  Using this command in an empty line
  creates a new fixed-width region.

#+cindex: storing link, in a source code buffer
Calling ~org-store-link~ (see [[*Handling Links]]) while editing a source
code example in a temporary buffer created with {{{kbd(C-c ')}}}
prompts for a label.  Make sure that it is unique in the current
buffer, and insert it with the proper formatting like =(ref:label)= at
the end of the current line.  Then the label is stored as a link
=(label)=, for retrieval with {{{kbd(C-c C-l)}}}.

** Images
:PROPERTIES:
:DESCRIPTION: Display an image.
:END:

#+cindex: inlining images
#+cindex: images, markup rules
An image is a link to an image file[fn:: What Emacs considers to be an
image depends on ~image-file-name-extensions~ and
~image-file-name-regexps~.] that does not have a description part, for
example

: ./img/cat.jpg

If you wish to define a caption for the image (see [[*Captions]]) and
maybe a label for internal cross references (see [[*Internal Links]]),
make sure that the link is on a line by itself and precede it with
=CAPTION= and =NAME= keywords as follows:

#+begin_example
,#+CAPTION: This is the caption for the next figure link (or table)
,#+NAME:   fig:SED-HR4049
[[./img/a.jpg]]
#+end_example

Such images can be displayed within the buffer with the following
command:

- {{{kbd(C-c C-x C-v)}}} (~org-toggle-inline-images~) ::

  #+kindex: C-c C-x C-v
  #+findex: org-toggle-inline-images
  #+vindex: org-startup-with-inline-images
  Toggle the inline display of linked images.  When called with a
  prefix argument, also display images that do have a link
  description.  You can ask for inline images to be displayed at
  startup by configuring the variable
  ~org-startup-with-inline-images~[fn:: The variable
  ~org-startup-with-inline-images~ can be set within a buffer with the
  =STARTUP= options =inlineimages= and =noinlineimages=.].


  #+vindex: org-image-actual-width
  #+cindex: @samp{ORG-IMAGE-ACTUAL-WIDTH}, property
  By default, Org mode displays inline images according to their
  actual width.  You can customize the displayed image width using
  ~org-image-actual-width~ variable (globally) or
  =ORG-IMAGE-ACTUAL-WIDTH= property (subtree-level)[fn:: The width can
  be customized in Emacs >= 24.1, built with imagemagick support.].
  Their value can be the following:
  - (default) Non-nil, use the actual width of images when inlining them.
  - When set to a number, use imagemagick (when available) to set the
    image's width to this value.
  - When set to a number in a list, try to get the width from any
    =#+ATTR.*= keyword if it matches a width specification like:
    #+begin_example
    ,#+ATTR_HTML: :width 300px
    #+end_example
    and fall back on that number if none is found.
  - When set to nil, try to get the width from an =#+ATTR.*= keyword
    and fall back on the original width if none is found.


#+vindex: org-cycle-inline-images-display
Inline images can also be displayed when cycling the folding state.
When custom option ~org-cycle-inline-images-display~ is set, the
visible inline images under subtree will be displayed automatically.

** Captions
:PROPERTIES:
:DESCRIPTION: Describe tables, images...
:END:
#+cindex: captions, markup rules
#+cindex: @samp{CAPTION}, keyword

You can assign a caption to a specific part of a document by inserting
a =CAPTION= keyword immediately before it:

#+begin_example
,#+CAPTION: This is the caption for the next table (or link)
| ... | ... |
|-----+-----|
#+end_example

Optionally, the caption can take the form:

: #+CAPTION[Short caption]: Longer caption.

Even though images and tables are prominent examples of captioned
structures, the same caption mechanism can apply to many
others---e.g., LaTeX equations, source code blocks.  Depending on the
export back-end, those may or may not be handled.

** Horizontal Rules
:PROPERTIES:
:DESCRIPTION: Make a line.
:END:

#+cindex: horizontal rules, markup rules
A line consisting of only dashes, and at least 5 of them, is exported
as a horizontal line.

** Creating Footnotes
:PROPERTIES:
:DESCRIPTION: Edit and read footnotes.
:END:
#+cindex: footnotes

A footnote is started by a footnote marker in square brackets in
column 0, no indentation allowed.  It ends at the next footnote
definition, headline, or after two consecutive empty lines.  The
footnote reference is simply the marker in square brackets, inside
text.  Markers always start with =fn:=.  For example:

#+begin_example
The Org website[fn:1] now looks a lot better than it used to.
...
[fn:55] The link is: https://orgmode.org
#+end_example

Org mode extends the number-based syntax to /named/ footnotes and
optional inline definition.  Here are the valid references:

- =[fn:NAME]= ::

  A named footnote reference, where {{{var(NAME)}}} is a unique
  label word, or, for simplicity of automatic creation, a number.

- =[fn:: This is the inline definition of this footnote]= ::

  An anonymous footnote where the definition is given directly at the
  reference point.

- =[fn:NAME: a definition]= ::

  An inline definition of a footnote, which also specifies a name for
  the note.  Since Org allows multiple references to the same note,
  you can then use =[fn:NAME]= to create additional references.

#+vindex: org-footnote-auto-label
Footnote labels can be created automatically, or you can create names
yourself.  This is handled by the variable ~org-footnote-auto-label~
and its corresponding =STARTUP= keywords.  See the docstring of that
variable for details.

The following command handles footnotes:

- {{{kbd(C-c C-x f)}}} ::

  The footnote action command.

  #+kindex: C-c C-x f
  When point is on a footnote reference, jump to the definition.  When
  it is at a definition, jump to the---first---reference.

  #+vindex: org-footnote-define-inline
  #+vindex: org-footnote-section
  Otherwise, create a new footnote.  Depending on the variable
  ~org-footnote-define-inline~[fn:: The corresponding in-buffer
  setting is: =#+STARTUP: fninline= or =#+STARTUP: nofninline=.], the
  definition is placed right into the text as part of the reference,
  or separately into the location determined by the variable
  ~org-footnote-section~.

  When this command is called with a prefix argument, a menu of
  additional options is offered:

  #+attr_texinfo: :columns 0.1 0.9
  | {{{kbd(s)}}} | Sort the footnote definitions by reference sequence.               |
  | {{{kbd(r)}}} | Renumber the simple =fn:N= footnotes.                              |
  | {{{kbd(S)}}} | Short for first {{{kbd(r)}}}, then {{{kbd(s)}}} action.                        |
  | {{{kbd(n)}}} | Rename all footnotes into a =fn:1= ... =fn:n= sequence.            |
  | {{{kbd(d)}}} | Delete the footnote at point, including definition and references. |

  #+vindex: org-footnote-auto-adjust
  Depending on the variable ~org-footnote-auto-adjust~[fn:: The
  corresponding in-buffer options are =#+STARTUP: fnadjust= and
  =#+STARTUP: nofnadjust=.], renumbering and sorting footnotes can be
  automatic after each insertion or deletion.

- {{{kbd(C-c C-c)}}} ::

  #+kindex: C-c C-c
  If point is on a footnote reference, jump to the definition.  If it
  is at the definition, jump back to the reference.  When called at
  a footnote location with a prefix argument, offer the same menu as
  {{{kbd(C-c C-x f)}}}.

- {{{kbd(C-c C-o)}}} or {{{kbd(mouse-1/2)}}} ::

  #+kindex: C-c C-o
  #+kindex: mouse-1
  #+kindex: mouse-2
  Footnote labels are also links to the corresponding definition or
  reference, and you can use the usual commands to follow these links.

* Exporting
:PROPERTIES:
:DESCRIPTION: Sharing and publishing notes.
:END:
#+cindex: exporting

At some point you might want to print your notes, publish them on the
web, or share them with people not using Org.  Org can convert and
export documents to a variety of other formats while retaining as much
structure (see [[*Document Structure]]) and markup (see [[*Markup for Rich
Contents]]) as possible.

#+cindex: export back-end
The libraries responsible for translating Org files to other formats
are called /back-ends/.  Org ships with support for the following
back-ends:

- /ascii/ (ASCII format)
- /beamer/ (LaTeX Beamer format)
- /html/ (HTML format)
- /icalendar/ (iCalendar format)
- /latex/ (LaTeX format)
- /md/ (Markdown format)
- /odt/ (OpenDocument Text format)
- /org/ (Org format)
- /texinfo/ (Texinfo format)
- /man/ (Man page format)

Users can install libraries for additional formats from the Emacs
packaging system.  For easy discovery, these packages have a common
naming scheme: ~ox-NAME~, where {{{var(NAME)}}} is a format.  For
example, ~ox-koma-letter~ for /koma-letter/ back-end.  More libraries
can be found in the =org-contrib= repository (see [[*Installation]]).

#+vindex: org-export-backends
Org only loads back-ends for the following formats by default: ASCII,
HTML, iCalendar, LaTeX, and ODT.  Additional back-ends can be loaded
in either of two ways: by configuring the ~org-export-backends~
variable, or by requiring libraries in the Emacs init file.  For
example, to load the Markdown back-end, add this to your Emacs config:

#+begin_src emacs-lisp
(require 'ox-md)
#+end_src

** The Export Dispatcher
:PROPERTIES:
:DESCRIPTION: The main interface.
:END:
#+cindex: dispatcher, for export commands
#+cindex: export, dispatcher

The export dispatcher is the main interface for Org's exports.
A hierarchical menu presents the currently configured export formats.
Options are shown as easy toggle switches on the same screen.

#+vindex: org-export-dispatch-use-expert-ui
Org also has a minimal prompt interface for the export dispatcher.
When the variable ~org-export-dispatch-use-expert-ui~ is set to
a non-~nil~ value, Org prompts in the minibuffer.  To switch back to
the hierarchical menu, press {{{kbd(?)}}}.

- {{{kbd(C-c C-e)}}} (~org-export-dispatch~) ::
  #+kindex: C-c C-e
  #+findex: org-export-dispatch

  Invokes the export dispatcher interface.  The options show default
  settings.  The {{{kbd(C-u)}}} prefix argument preserves options from
  the previous export, including any subtree selections.

Org exports the entire buffer by default.  If the Org buffer has an
active region, then Org exports just that region.

Within the dispatcher interface, the following key combinations can
further alter what is exported, and how.

- {{{kbd(C-a)}}} ::
  #+kindex: C-c C-e C-a

  Toggle asynchronous export.  Asynchronous export uses an external
  Emacs process with a specially configured initialization file to
  complete the exporting process in the background, without tying-up
  Emacs.  This is particularly useful when exporting long documents.

  Output from an asynchronous export is saved on the /export stack/.
  To view this stack, call the export dispatcher with a double
  {{{kbd(C-u)}}} prefix argument.  If already in the export dispatcher
  menu, {{{kbd(&)}}} displays the stack.

  #+vindex: org-export-in-background
  You can make asynchronous export the default by setting
  ~org-export-in-background~.

  #+vindex: org-export-async-init-file
  You can set the initialization file used by the background process
  by setting ~org-export-async-init-file~.

- {{{kbd(C-b)}}} ::
  #+kindex: C-c C-e C-b

  Toggle body-only export.  Useful for excluding headers and footers
  in the export.  Affects only those back-end formats that have
  sections like =<head>...</head>= in HTML.

- {{{kbd(C-s)}}} ::
  #+kindex: C-c C-e C-s

  Toggle subtree export.  When turned on, Org exports only the
  subtree starting from point position at the time the export
  dispatcher was invoked.  Org uses the top heading of this subtree
  as the document's title.  If point is not on a heading, Org uses the
  nearest enclosing header.  If point is in the document preamble, Org
  signals an error and aborts export.

  #+vindex: org-export-initial-scope
  To make subtree export the default, customize the variable
  ~org-export-initial-scope~.

- {{{kbd(C-v)}}} ::
  #+kindex: C-c C-e C-v

  Toggle visible-only export.  This is useful for exporting only
  certain parts of an Org document by adjusting the visibility of
  particular headings.  See also [[*Sparse Trees]].

** Export Settings
:PROPERTIES:
:DESCRIPTION: Common export settings.
:END:
#+cindex: options, for export
#+cindex: Export, settings

#+cindex: @samp{OPTIONS}, keyword
Export options can be set: globally with variables; for an individual
file by making variables buffer-local with in-buffer settings (see
[[*Summary of In-Buffer Settings]]); by setting individual keywords or
specifying them in compact form with the =OPTIONS= keyword; or for
a tree by setting properties (see [[*Properties and Columns]]).  Options
set at a specific level override options set at a more general level.

#+cindex: @samp{SETUPFILE}, keyword
In-buffer settings may appear anywhere in the file, either directly or
indirectly through a file included using =#+SETUPFILE: filename or
URL= syntax.  Option keyword sets tailored to a particular back-end
can be inserted from the export dispatcher (see [[*The Export
Dispatcher]]) using the =Insert template= command by pressing
{{{kbd(#)}}}.  To insert keywords individually, a good way to make
sure the keyword is correct is to type =#+= and then to use
{{{kbd(M-TAB)}}}[fn:6] for completion.

The export keywords available for every back-end, and their equivalent
global variables, include:

- =AUTHOR= ::

  #+cindex: @samp{AUTHOR}, keyword
  #+vindex: user-full-name
  The document author (~user-full-name~).

- =CREATOR= ::

  #+cindex: @samp{CREATOR}, keyword
  #+vindex: org-expot-creator-string
  Entity responsible for output generation
  (~org-export-creator-string~).

- =DATE= ::

  #+cindex: @samp{DATE}, keyword
  #+vindex: org-export-date-timestamp-format
  A date or a time-stamp[fn:: The variable
  ~org-export-date-timestamp-format~ defines how this timestamp are
  exported.].

- =EMAIL= ::

  #+cindex: @samp{EMAIL}, keyword
  #+vindex: user-mail-address
  The email address (~user-mail-address~).

- =LANGUAGE= ::

  #+cindex: @samp{LANGUAGE}, keyword
  #+vindex: org-export-default-language
  Language to use for translating certain strings
  (~org-export-default-language~).  With =#+LANGUAGE: fr=, for
  example, Org translates =Table of contents= to the French =Table des
  matières=[fn:41].

- =SELECT_TAGS= ::

  #+cindex: @samp{SELECT_TAGS}, keyword
  #+vindex: org-export-select-tags
  The default value is =("export")=.  When a tree is tagged with
  =export= (~org-export-select-tags~), Org selects that tree and its
  subtrees for export.  Org excludes trees with =noexport= tags, see
  below.  When selectively exporting files with =export= tags set, Org
  does not export any text that appears before the first headline.

- =EXCLUDE_TAGS= ::

  #+cindex: @samp{EXCLUDE_TAGS}, keyword
  #+vindex: org-export-exclude-tags
  The default value is =("noexport")=.  When a tree is tagged with
  =noexport= (~org-export-exclude-tags~), Org excludes that tree and
  its subtrees from export.  Entries tagged with =noexport= are
  unconditionally excluded from the export, even if they have an
  =export= tag.  Even if a subtree is not exported, Org executes any
  code blocks contained there.

- =TITLE= ::

  #+cindex: @samp{TITLE}, keyword
  #+cindex: document title
  Org displays this title.  For long titles, use multiple =#+TITLE=
  lines.

- =EXPORT_FILE_NAME= ::

  #+cindex: @samp{EXPORT_FILE_NAME}, keyword
  The name of the output file to be generated.  Otherwise, Org
  generates the file name based on the buffer name and the extension
  based on the back-end format.

The =OPTIONS= keyword is a compact form.  To configure multiple
options, use several =OPTIONS= lines.  =OPTIONS= recognizes the
following arguments.

- ~'~ ::

  #+vindex: org-export-with-smart-quotes
  Toggle smart quotes (~org-export-with-smart-quotes~).  Depending on
  the language used, when activated, Org treats pairs of double quotes
  as primary quotes, pairs of single quotes as secondary quotes, and
  single quote marks as apostrophes.

- ~*~ ::

  #+vindex: org-export-with-emphasize
  Toggle emphasized text (~org-export-with-emphasize~).

- ~-~ ::

  #+vindex: org-export-with-special-strings
  Toggle conversion of special strings
  (~org-export-with-special-strings~).

- ~:~ ::

  #+vindex: org-export-with-fixed-width
  Toggle fixed-width sections (~org-export-with-fixed-width~).

- ~<~ ::

  #+vindex: org-export-with-timestamps
  Toggle inclusion of time/date active/inactive stamps
  (~org-export-with-timestamps~).

- ~\n~ ::

  #+vindex: org-export-preserve-breaks
  Toggles whether to preserve line breaks
  (~org-export-preserve-breaks~).

- ~^~ ::

  #+vindex: org-export-with-sub-superscripts
  Toggle TeX-like syntax for sub- and superscripts.  If you write
  =^:{}=, =a_{b}= is interpreted, but the simple =a_b= is left as it
  is (~org-export-with-sub-superscripts~).

- ~arch~ ::

  #+vindex: org-export-with-archived-trees
  Configure how archived trees are exported.  When set to ~headline~,
  the export process skips the contents and processes only the
  headlines (~org-export-with-archived-trees~).

- ~author~ ::

  #+vindex: org-export-with-author
  Toggle inclusion of author name into exported file
  (~org-export-with-author~).

- ~broken-links~ ::

  #+vindex: org-export-with-broken-links
  Toggles if Org should continue exporting upon finding a broken
  internal link.  When set to ~mark~, Org clearly marks the problem
  link in the output (~org-export-with-broken-links~).

- ~c~ ::

  #+vindex: org-export-with-clocks
  Toggle inclusion of =CLOCK= keywords (~org-export-with-clocks~).

- ~creator~ ::

  #+vindex: org-export-with-creator
  Toggle inclusion of creator information in the exported file
  (~org-export-with-creator~).

- ~d~ ::

  #+vindex: org-export-with-drawers
  Toggles inclusion of drawers, or list of drawers to include, or list
  of drawers to exclude (~org-export-with-drawers~).

- ~date~ ::

  #+vindex: org-export-with-date
  Toggle inclusion of a date into exported file
  (~org-export-with-date~).

- ~e~ ::

  #+vindex: org-export-with-entities
  Toggle inclusion of entities (~org-export-with-entities~).

- ~email~ ::

  #+vindex: org-export-with-email
  Toggle inclusion of the author's e-mail into exported file
  (~org-export-with-email~).

- ~f~ ::

  #+vindex: org-export-with-footnotes
  Toggle the inclusion of footnotes (~org-export-with-footnotes~).

- ~H~ ::

  #+vindex: org-export-headline-levels
  Set the number of headline levels for export
  (~org-export-headline-levels~).  Below that level, headlines are
  treated differently.  In most back-ends, they become list items.

- ~inline~ ::

  #+vindex: org-export-with-inlinetasks
  Toggle inclusion of inlinetasks (~org-export-with-inlinetasks~).

- ~num~ ::

  #+vindex: org-export-with-section-numbers
  #+cindex: @samp{UNNUMBERED}, property
  Toggle section-numbers (~org-export-with-section-numbers~).  When
  set to number N, Org numbers only those headlines at level N or
  above.  Set =UNNUMBERED= property to non-~nil~ to disable numbering
  of heading and subheadings entirely.  Moreover, when the value is
  =notoc= the headline, and all its children, do not appear in the
  table of contents either (see [[*Table of Contents]]).

- ~p~ ::

  #+vindex: org-export-with-planning
  Toggle export of planning information (~org-export-with-planning~).
  "Planning information" comes from lines located right after the
  headline and contain any combination of these cookies: =SCHEDULED=,
  =DEADLINE=, or =CLOSED=.

- ~pri~ ::

  #+vindex: org-export-with-priority
  Toggle inclusion of priority cookies
  (~org-export-with-priority~).

- ~prop~ ::

  #+vindex: org-export-with-properties
  Toggle inclusion of property drawers, or list the properties to
  include (~org-export-with-properties~).

- ~stat~ ::

  #+vindex: org-export-with-statistics-cookies
  Toggle inclusion of statistics cookies
  (~org-export-with-statistics-cookies~).

- ~tags~ ::

  #+vindex: org-export-with-tags
  Toggle inclusion of tags, may also be ~not-in-toc~
  (~org-export-with-tags~).

- ~tasks~ ::

  #+vindex: org-export-with-tasks
  Toggle inclusion of tasks (TODO items); or ~nil~ to remove all
  tasks; or ~todo~ to remove done tasks; or list the keywords to keep
  (~org-export-with-tasks~).

- ~tex~ ::

  #+vindex: org-export-with-latex
  ~nil~ does not export; ~t~ exports; ~verbatim~ keeps everything in
  verbatim (~org-export-with-latex~).

- ~timestamp~ ::

  #+vindex: org-export-time-stamp-file
  Toggle inclusion of the creation time in the exported file
  (~org-export-time-stamp-file~).

- ~title~ ::

  #+vindex: org-export-with-title
  Toggle inclusion of title (~org-export-with-title~).

- ~toc~ ::

  #+vindex: org-export-with-toc
  Toggle inclusion of the table of contents, or set the level limit
  (~org-export-with-toc~).

- ~todo~ ::

  #+vindex: org-export-with-todo-keywords
  Toggle inclusion of TODO keywords into exported text
  (~org-export-with-todo-keywords~).

- ~|~ ::

  #+vindex: org-export-with-tables
  Toggle inclusion of tables (~org-export-with-tables~).

When exporting subtrees, special node properties can override the
above keywords.  These properties have an =EXPORT_= prefix.  For
example, =DATE= becomes, =EXPORT_DATE= when used for a specific
subtree.  Except for =SETUPFILE=, all other keywords listed above
have an =EXPORT_= equivalent.

#+cindex: @samp{BIND}, keyword
#+vindex: org-export-allow-bind-keywords
If ~org-export-allow-bind-keywords~ is non-~nil~, Emacs variables can
become buffer-local during export by using the =BIND= keyword.  Its
syntax is =#+BIND: variable value=.  This is particularly useful for
in-buffer settings that cannot be changed using keywords.

** Table of Contents
:PROPERTIES:
:DESCRIPTION: The if and where of the table of contents.
:END:
#+cindex: table of contents
#+cindex: list of tables
#+cindex: list of listings

#+cindex: @samp{toc}, in @samp{OPTIONS} keyword
#+vindex: org-export-with-toc
The table of contents includes all headlines in the document.  Its
depth is therefore the same as the headline levels in the file.  If
you need to use a different depth, or turn it off entirely, set the
~org-export-with-toc~ variable accordingly.  You can achieve the same
on a per file basis, using the following =toc= item in =OPTIONS=
keyword:

#+begin_example
,#+OPTIONS: toc:2          (only include two levels in TOC)
,#+OPTIONS: toc:nil        (no default TOC at all)
#+end_example

#+cindex: excluding entries from table of contents
#+cindex: table of contents, exclude entries
Org includes both numbered and unnumbered headlines in the table of
contents[fn:42].  If you need to exclude an unnumbered headline,
along with all its children, set the =UNNUMBERED= property to =notoc=
value.

#+begin_example
,* Subtree not numbered, not in table of contents either
  :PROPERTIES:
  :UNNUMBERED: notoc
  :END:
#+end_example

#+cindex: @samp{TOC}, keyword
Org normally inserts the table of contents directly before the first
headline of the file.  To move the table of contents to a different
location, first turn off the default with ~org-export-with-toc~
variable or with =#+OPTIONS: toc:nil=.  Then insert =#+TOC: headlines
N= at the desired location(s).

#+begin_example
,#+OPTIONS: toc:nil
...
,#+TOC: headlines 2
#+end_example

To adjust the table of contents depth for a specific section of the
Org document, append an additional =local= parameter.  This parameter
becomes a relative depth for the current level.  The following example
inserts a local table of contents, with direct children only.

#+begin_example
,* Section
,#+TOC: headlines 1 local
#+end_example

Note that for this feature to work properly in LaTeX export, the Org
file requires the inclusion of the titletoc package.  Because of
compatibility issues, titletoc has to be loaded /before/ hyperref.
Customize the ~org-latex-default-packages-alist~ variable.

The following example inserts a table of contents that links to the
children of the specified target.

#+begin_example
,* Target
  :PROPERTIES:
  :CUSTOM_ID: TargetSection
  :END:
,** Heading A
,** Heading B
,* Another section
,#+TOC: headlines 1 :target #TargetSection
#+end_example

The =:target= attribute is supported in HTML, Markdown, ODT, and ASCII export.

Use the =TOC= keyword to generate list of tables---respectively, all
listings---with captions.

#+begin_example
,#+TOC: listings
,#+TOC: tables
#+end_example

#+cindex: @samp{ALT_TITLE}, property
Normally Org uses the headline for its entry in the table of contents.
But with =ALT_TITLE= property, a different entry can be specified for
the table of contents.

** Include Files
:PROPERTIES:
:DESCRIPTION: Include additional files into a document.
:END:
#+cindex: include files, during export
#+cindex: export, include files
#+cindex: @samp{INCLUDE}, keyword

During export, you can include the content of another file.  For
example, to include your =.emacs= file, you could use:

: #+INCLUDE: "~/.emacs" src emacs-lisp

#+texinfo: @noindent
The first parameter is the file name to include.  The optional second
parameter specifies the block type: =example=, =export= or =src=.  The
optional third parameter specifies the source code language to use for
formatting the contents.  This is relevant to both =export= and =src=
block types.

If an included file is specified as having a markup language, Org
neither checks for valid syntax nor changes the contents in any way.
For example and source blocks, Org code-escapes the contents before
inclusion.

#+cindex: @samp{minlevel}, include
If an included file is not specified as having any markup language,
Org assumes it be in Org format and proceeds as usual with a few
exceptions.  Org makes the footnote labels (see [[*Creating Footnotes]])
in the included file local to that file.  The contents of the included
file belong to the same structure---headline, item---containing the
=INCLUDE= keyword.  In particular, headlines within the file become
children of the current section.  That behavior can be changed by
providing an additional keyword parameter, =:minlevel=.  It shifts the
headlines in the included file to become the lowest level.  For
example, this syntax makes the included file a sibling of the current
top-level headline:

: #+INCLUDE: "~/my-book/chapter2.org" :minlevel 1

#+cindex: @samp{lines}, include
Inclusion of only portions of files are specified using ranges
parameter with =:lines= keyword.  The line at the upper end of the
range will not be included.  The start and/or the end of the range may
be omitted to use the obvious defaults.

| =#+INCLUDE: "~/.emacs" :lines "5-10"= | Include lines 5 to 10, 10 excluded |
| =#+INCLUDE: "~/.emacs" :lines "-10"=  | Include lines 1 to 10, 10 excluded |
| =#+INCLUDE: "~/.emacs" :lines "10-"=  | Include lines from 10 to EOF       |

Inclusions may specify a file-link to extract an object matched by
~org-link-search~[fn:43] (see [[*Search Options in File Links]]).  The
ranges for =:lines= keyword are relative to the requested element.
Therefore,

: #+INCLUDE: "./paper.org::*conclusion" :lines 1-20

#+texinfo: @noindent
includes the first 20 lines of the headline named =conclusion=.

#+cindex: @samp{only-contents}, include
To extract only the contents of the matched object, set
=:only-contents= property to non-~nil~.  This omits any planning lines
or property drawers.  For example, to include the body of the heading
with the custom ID =theory=, you can use

: #+INCLUDE: "./paper.org::#theory" :only-contents t

The following command allows navigating to the included document:

- {{{kbd(C-c ')}}} (~org-edit-special~) ::
  #+kindex: C-c '
  #+findex: org-edit-special

  Visit the included file at point.

** Macro Replacement
:PROPERTIES:
:DESCRIPTION: Use macros to create templates.
:END:
#+cindex: macro replacement, during export
#+cindex: @samp{MACRO}, keyword

#+vindex: org-export-global-macros
Macros replace text snippets during export.  Macros are defined
globally in ~org-export-global-macros~, or document-wise with the
following syntax:

: #+MACRO: name   replacement text; $1, $2 are arguments

#+texinfo: @noindent
which can be referenced using ={{{name(arg1, arg2)}}}=[fn:44].  For
example

#+begin_example
,#+MACRO: poem Rose is $1, violet's $2. Life's ordered: Org assists you.
{{{poem(red,blue)}}}
#+end_example

#+texinfo: @noindent
becomes

: Rose is red, violet's blue.  Life's ordered: Org assists you.

As a special case, Org parses any replacement text starting with
=(eval= as an Emacs Lisp expression and evaluates it accordingly.
Within such templates, arguments become strings.  Thus, the following
macro

: #+MACRO: gnustamp (eval (concat "GNU/" (capitalize $1)))

#+texinfo: @noindent
turns ={{{gnustamp(linux)}}}= into =GNU/Linux= during export.

Org recognizes macro references in following Org markup areas:
paragraphs, headlines, verse blocks, tables cells and lists.  Org also
recognizes macro references in keywords, such as =CAPTION=, =TITLE=,
=AUTHOR=, =DATE=, and for some back-end specific export options.

Org comes with following pre-defined macros:

#+attr_texinfo: :sep ;
- ={{{keyword(NAME)}}}=; ={{{title}}}=; ={{{author}}}=; ={{{email}}}= ::

  #+cindex: @samp{keyword}, macro
  #+cindex: @samp{title}, macro
  #+cindex: @samp{author}, macro
  #+cindex: @samp{email}, macro
  The =keyword= macro collects all values from {{{var(NAME)}}}
  keywords throughout the buffer, separated with white space.
  =title=, =author= and =email= macros are shortcuts for,
  respectively, ={{{keyword(TITLE)}}}=, ={{{keyword(AUTHOR)}}}= and
  ={{{keyword(EMAIL)}}}=.

- ={{{date}}}=; ={{{date(FORMAT)}}}= ::

  #+cindex: @samp{date}, macro
  This macro refers to the =DATE= keyword.  {{{var(FORMAT)}}} is an
  optional argument to the =date= macro that is used only if =DATE= is
  a single timestamp.  {{{var(FORMAT)}}} should be a format string
  understood by ~format-time-string~.

- ={{{time(FORMAT)}}}=; ={{{modification-time(FORMAT, VC)}}}= ::

  #+cindex: @samp{time}, macro
  #+cindex: @samp{modification-time}, macro
  These macros refer to the document's date and time of export and
  date and time of modification.  {{{var(FORMAT)}}} is a string
  understood by ~format-time-string~.  If the second argument to the
  ~modification-time~ macro is non-~nil~, Org uses =vc.el= to retrieve
  the document's modification time from the version control system.
  Otherwise Org reads the file attributes.

- ={{{input-file}}}= ::

  #+cindex: @samp{input-file}, macro
  This macro refers to the filename of the exported file.

- ={{{property(PROPERTY-NAME)}}}=; ={{{property(PROPERTY-NAME, SEARCH OPTION)}}}= ::

  #+cindex: @samp{property}, macro
  This macro returns the value of property {{{var(PROPERTY-NAME)}}} in
  the current entry.  If {{{var(SEARCH-OPTION)}}} (see [[*Search
  Options in File Links]]) refers to a remote entry, use it instead.

- ={{{n}}}=; ={{{n(NAME)}}}=; ={{{n(NAME, ACTION)}}}= ::

  #+cindex: @samp{n}, macro
  #+cindex: counter, macro
  This macro implements custom counters by returning the number of
  times the macro has been expanded so far while exporting the buffer.
  You can create more than one counter using different {{{var(NAME)}}}
  values.  If {{{var(ACTION)}}} is =-=, previous value of the counter
  is held, i.e., the specified counter is not incremented.  If the
  value is a number, the specified counter is set to that value.  If
  it is any other non-empty string, the specified counter is reset
  to 1.  You may leave {{{var(NAME)}}} empty to reset the default
  counter.

#+cindex: @samp{results}, macro
Moreover, inline source blocks (see [[*Structure of Code Blocks]]) use the
special =results= macro to mark their output.  As such, you are
advised against re-defining it, unless you know what you are doing.

#+vindex: org-hide-macro-markers
The surrounding brackets can be made invisible by setting
~org-hide-macro-markers~ to a non-~nil~ value.

Org expands macros at the very beginning of the export process.

** Comment Lines
:PROPERTIES:
:DESCRIPTION: What will not be exported.
:END:
#+cindex: exporting, not

#+cindex: comment lines
Lines starting with zero or more whitespace characters followed by one
=#= and a whitespace are treated as comments and, as such, are not
exported.

#+cindex: @samp{BEGIN_COMMENT}
#+cindex: comment block
Likewise, regions surrounded by =#+BEGIN_COMMENT= ... =#+END_COMMENT=
are not exported.

#+cindex: comment trees
Finally, a =COMMENT= keyword at the beginning of an entry, but after
any other keyword or priority cookie, comments out the entire subtree.
In this case, the subtree is not exported and no code block within it
is executed either[fn:: For a less drastic behavior, consider using a
select tag (see [[*Export Settings]]) instead.].  The command below
helps changing the comment status of a headline.

- {{{kbd(C-c ;)}}} (~org-toggle-comment~) ::
  #+kindex: C-c ;
  #+findex: org-toggle-comment

  Toggle the =COMMENT= keyword at the beginning of an entry.

** ASCII/Latin-1/UTF-8 export
:PROPERTIES:
:DESCRIPTION: Exporting to flat files with encoding.
:END:
#+cindex: ASCII export
#+cindex: Latin-1 export
#+cindex: UTF-8 export

ASCII export produces an output file containing only plain ASCII
characters.  This is the simplest and most direct text output.  It
does not contain any Org markup.  Latin-1 and UTF-8 export use
additional characters and symbols available in these encoding
standards.  All three of these export formats offer the most basic of
text output for maximum portability.

#+vindex: org-ascii-text-width
On export, Org fills and justifies text according to the text width
set in ~org-ascii-text-width~.

#+vindex: org-ascii-links-to-notes
Org exports links using a footnote-like style where the descriptive
part is in the text and the link is in a note before the next heading.
See the variable ~org-ascii-links-to-notes~ for details.

*** ASCII export commands
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+attr_texinfo: :sep ,
- {{{kbd(C-c C-e t a)}}} (~org-ascii-export-to-ascii~), {{{kbd(C-c C-e t l)}}}, {{{kbd(C-c C-e t u)}}} ::
  #+kindex: C-c C-e t a
  #+kindex: C-c C-e t l
  #+kindex: C-c C-e t u
  #+findex: org-ascii-export-to-ascii

  Export as an ASCII file with a =.txt= extension.  For =myfile.org=,
  Org exports to =myfile.txt=, overwriting without warning.  For
  =myfile.txt=, Org exports to =myfile.txt.txt= in order to prevent
  data loss.

- {{{kbd(C-c C-e t A)}}} (~org-ascii-export-to-ascii~), {{{kbd(C-c C-e t L)}}}, {{{kbd(C-c C-e t U)}}} ::
  #+kindex: C-c C-e t A
  #+kindex: C-c C-e t L
  #+kindex: C-c C-e t U
  #+findex: org-ascii-export-as-ascii

  Export to a temporary buffer.  Does not create a file.

*** ASCII specific export settings
:PROPERTIES:
:UNNUMBERED: notoc
:END:

The ASCII export back-end has one extra keyword for customizing ASCII
output.  Setting this keyword works similar to the general options
(see [[*Export Settings]]).

- =SUBTITLE= ::

  #+cindex: @samp{SUBTITLE}, keyword
  The document subtitle.  For long subtitles, use multiple
  =#+SUBTITLE= lines in the Org file.  Org prints them on one
  continuous line, wrapping into multiple lines if necessary.

*** Header and sectioning structure
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Org converts the first three outline levels into headlines for ASCII
export.  The remaining levels are turned into lists.  To change this
cut-off point where levels become lists, see [[*Export Settings]].

*** Quoting ASCII text
:PROPERTIES:
:UNNUMBERED: notoc
:END:

To insert text within the Org file by the ASCII back-end, use one the
following constructs, inline, keyword, or export block:

#+cindex: @samp{ASCII}, keyword
#+cindex: @samp{BEGIN_EXPORT ascii}
#+begin_example
Inline text @@ascii:and additional text@@ within a paragraph.

,#+ASCII: Some text

,#+BEGIN_EXPORT ascii
Org exports text in this block only when using ASCII back-end.
,#+END_EXPORT
#+end_example

*** ASCII specific attributes
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: @samp{ATTR_ASCII}, keyword
#+cindex: horizontal rules, in ASCII export

ASCII back-end recognizes only one attribute, =:width=, which
specifies the width of a horizontal rule in number of characters.  The
keyword and syntax for specifying widths is:

#+begin_example
,#+ATTR_ASCII: :width 10
-----
#+end_example

*** ASCII special blocks
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+cindex: special blocks, in ASCII export
#+cindex: @samp{BEGIN_JUSTIFYLEFT}
#+cindex: @samp{BEGIN_JUSTIFYRIGHT}

Besides =#+BEGIN_CENTER= blocks (see [[*Paragraphs]]), ASCII back-end has
these two left and right justification blocks:

#+begin_example
,#+BEGIN_JUSTIFYLEFT
It's just a jump to the left...
,#+END_JUSTIFYLEFT

,#+BEGIN_JUSTIFYRIGHT
...and then a step to the right.
,#+END_JUSTIFYRIGHT
#+end_example

** Beamer Export
:PROPERTIES:
:DESCRIPTION: Producing presentations and slides.
:END:
#+cindex: Beamer export

Org uses Beamer export to convert an Org file tree structure into
high-quality interactive slides for presentations.  Beamer is a LaTeX
document class for creating presentations in PDF, HTML, and other
popular display formats.

*** Beamer export commands
:PROPERTIES:
:DESCRIPTION: For creating Beamer documents.
:END:

- {{{kbd(C-c C-e l b)}}} (~org-beamer-export-to-latex~) ::
  #+kindex: C-c C-e l b
  #+findex: org-beamer-export-to-latex

  Export as LaTeX file with a =.tex= extension.  For =myfile.org=, Org
  exports to =myfile.tex=, overwriting without warning.

- {{{kbd(C-c C-e l B)}}} (~org-beamer-export-as-latex~) ::
  #+kindex: C-c C-e l B
  #+findex: org-beamer-export-as-latex

  Export to a temporary buffer.  Does not create a file.

- {{{kbd(C-c C-e l P)}}} (~org-beamer-export-to-pdf~) ::
  #+kindex: C-c C-e l P
  #+findex: org-beamer-export-to-pdf

  Export as LaTeX file and then convert it to PDF format.

- {{{kbd(C-c C-e l O)}}} ::
  #+kindex: C-c C-e l O

  Export as LaTeX file, convert it to PDF format, and then open the
  PDF file.

*** Beamer specific export settings
:PROPERTIES:
:DESCRIPTION: For customizing Beamer export.
:END:

Beamer export back-end has several additional keywords for customizing
Beamer output.  These keywords work similar to the general options
settings (see [[*Export Settings]]).

- =BEAMER_THEME= ::

  #+cindex: @samp{BEAMER_THEME}, keyword
  #+vindex: org-beamer-theme
  The Beamer layout theme (~org-beamer-theme~).  Use square brackets
  for options.  For example:

  : #+BEAMER_THEME: Rochester [height=20pt]

- =BEAMER_FONT_THEME= ::

  #+cindex: @samp{BEAMER_FONT_THEME}, keyword
  The Beamer font theme.

- =BEAMER_INNER_THEME= ::

  #+cindex: @samp{BEAMER_INNER_THEME}, keyword
  The Beamer inner theme.

- =BEAMER_OUTER_THEME= ::

  #+cindex: @samp{BEAMER_OUTER_THEME}, keyword
  The Beamer outer theme.

- =BEAMER_HEADER= ::

  #+cindex: @samp{BEAMER_HEADER}, keyword
  Arbitrary lines inserted in the preamble, just before the =hyperref=
  settings.

- =DESCRIPTION= ::

  #+cindex: @samp{DESCRIPTION}, keyword
  The document description.  For long descriptions, use multiple
  =DESCRIPTION= keywords.  By default, =hyperref= inserts
  =DESCRIPTION= as metadata.  Use ~org-latex-hyperref-template~ to
  configure document metadata.  Use ~org-latex-title-command~ to
  configure typesetting of description as part of front matter.

- =KEYWORDS= ::

  #+cindex: @samp{KEYWORDS}, keyword
  The keywords for defining the contents of the document.  Use
  multiple =KEYWORDS= lines if necessary.  By default, =hyperref=
  inserts =KEYWORDS= as metadata.  Use ~org-latex-hyperref-template~
  to configure document metadata.  Use ~org-latex-title-command~ to
  configure typesetting of keywords as part of front matter.

- =SUBTITLE= ::

  #+cindex: @samp{SUBTITLE}, keyword
  Document's subtitle.  For typesetting, use
  ~org-beamer-subtitle-format~ string.  Use
  ~org-latex-hyperref-template~ to configure document metadata.  Use
  ~org-latex-title-command~ to configure typesetting of subtitle as
  part of front matter.

*** Frames and Blocks in Beamer
:PROPERTIES:
:DESCRIPTION: For composing Beamer slides.
:END:

Org transforms heading levels into Beamer's sectioning elements,
frames and blocks.  Any Org tree with a not-too-deep-level nesting
should in principle be exportable as a Beamer presentation.

-
  #+vindex: org-beamer-frame-level
  Org headlines become Beamer frames when the heading level in Org is
  equal to ~org-beamer-frame-level~ or =H= value in a =OPTIONS= line
  (see [[*Export Settings]]).

  #+cindex: @samp{BEAMER_ENV}, property
  Org overrides headlines to frames conversion for the current tree of
  an Org file if it encounters the =BEAMER_ENV= property set to
  =frame= or =fullframe=.  Org ignores whatever
  ~org-beamer-frame-level~ happens to be for that headline level in
  the Org tree.  In Beamer terminology, a full frame is a frame
  without its title.

- Org exports a Beamer frame's objects as block environments.  Org can
  enforce wrapping in special block types when =BEAMER_ENV= property
  is set[fn:45].  For valid values see
  ~org-beamer-environments-default~.  To add more values, see
  ~org-beamer-environments-extra~.
  #+vindex: org-beamer-environments-default
  #+vindex: org-beamer-environments-extra

-
  #+cindex: @samp{BEAMER_REF}, property
  If =BEAMER_ENV= is set to =appendix=, Org exports the entry as an
  appendix.  When set to =note=, Org exports the entry as a note
  within the frame or between frames, depending on the entry's heading
  level.  When set to =noteNH=, Org exports the entry as a note
  without its title.  When set to =againframe=, Org exports the entry
  with =\againframe= command, which makes setting the =BEAMER_REF=
  property mandatory because =\againframe= needs frame to resume.

  When =ignoreheading= is set, Org export ignores the entry's headline
  but not its content.  This is useful for inserting content between
  frames.  It is also useful for properly closing a =column=
  environment.

  #+cindex: @samp{BEAMER_ACT}, property
  #+cindex: @samp{BEAMER_OPT}, property
  When =BEAMER_ACT= is set for a headline, Org export translates that
  headline as an overlay or action specification.  When enclosed in
  square brackets, Org export makes the overlay specification
  a default.  Use =BEAMER_OPT= to set any options applicable to the
  current Beamer frame or block.  The Beamer export back-end wraps
  with appropriate angular or square brackets.  It also adds the
  =fragile= option for any code that may require a verbatim block.

  #+cindex: @samp{BEAMER_COL}, property
  To create a column on the Beamer slide, use the =BEAMER_COL=
  property for its headline in the Org file.  Set the value of
  =BEAMER_COL= to a decimal number representing the fraction of the
  total text width.  Beamer export uses this value to set the column's
  width and fills the column with the contents of the Org entry.  If
  the Org entry has no specific environment defined, Beamer export
  ignores the heading.  If the Org entry has a defined environment,
  Beamer export uses the heading as title.  Behind the scenes, Beamer
  export automatically handles LaTeX column separations for contiguous
  headlines.  To manually adjust them for any unique configurations
  needs, use the =BEAMER_ENV= property.

*** Beamer specific syntax
:PROPERTIES:
:DESCRIPTION: For using in Org documents.
:END:

Since Org's Beamer export back-end is an extension of the LaTeX
back-end, it recognizes other LaTeX specific syntax---for example,
=#+LATEX:= or =#+ATTR_LATEX:=.  See [[*LaTeX Export]], for details.

Beamer export wraps the table of contents generated with =toc:t=
=OPTION= keyword in a =frame= environment.  Beamer export does not
wrap the table of contents generated with =TOC= keyword (see [[*Table of
Contents]]).  Use square brackets for specifying options.

: #+TOC: headlines [currentsection]

Insert Beamer-specific code using the following constructs:

#+cindex: @samp{BEAMER}, keyword
#+cindex: @samp{BEGIN_EXPORT beamer}
#+begin_example
,#+BEAMER: \pause

,#+BEGIN_EXPORT beamer
  Only Beamer export back-end exports this.
,#+END_EXPORT

Text @@beamer:some code@@ within a paragraph.
#+end_example

Inline constructs, such as the last one above, are useful for adding
overlay specifications to objects with ~bold~, ~item~, ~link~,
~radio-target~ and ~target~ types.  Enclose the value in angular
brackets and place the specification at the beginning of the object as
shown in this example:

:  A *@@beamer:<2->@@useful* feature

#+cindex: @samp{ATTR_BEAMER}, keyword
Beamer export recognizes the =ATTR_BEAMER= keyword with the following
attributes from Beamer configurations: =:environment= for changing
local Beamer environment, =:overlay= for specifying Beamer overlays in
angular or square brackets, and =:options= for inserting optional
arguments.

#+begin_example
,#+ATTR_BEAMER: :environment nonindentlist
- item 1, not indented
- item 2, not indented
- item 3, not indented
#+end_example

#+begin_example
,#+ATTR_BEAMER: :overlay <+->
- item 1
- item 2
#+end_example

#+begin_example
,#+ATTR_BEAMER: :options [Lagrange]
Let $G$ be a finite group, and let $H$ be
a subgroup of $G$.  Then the order of $H$ divides the order of $G$.
#+end_example

*** Editing support
:PROPERTIES:
:DESCRIPTION: Editing support.
:END:

Org Beamer mode is a special minor mode for faster editing of Beamer
documents.

: #+STARTUP: beamer

- {{{kbd(C-c C-b)}}} (~org-beamer-select-environment~) ::
  #+kindex: C-c C-b
  #+findex: org-beamer-select-environment

  Org Beamer mode provides this key for quicker selections in Beamer
  normal environments, and for selecting the =BEAMER_COL= property.

*** A Beamer example
:PROPERTIES:
:DESCRIPTION: A complete presentation.
:END:

Here is an example of an Org document ready for Beamer export.

#+begin_example
,#+TITLE: Example Presentation
,#+AUTHOR: Carsten Dominik
,#+OPTIONS: H:2 toc:t num:t
,#+LATEX_CLASS: beamer
,#+LATEX_CLASS_OPTIONS: [presentation]
,#+BEAMER_THEME: Madrid
,#+COLUMNS: %45ITEM %10BEAMER_ENV(Env) %10BEAMER_ACT(Act) %4BEAMER_COL(Col)

,* This is the first structural section

,** Frame 1
,*** Thanks to Eric Fraga                                           :B_block:
    :PROPERTIES:
    :BEAMER_COL: 0.48
    :BEAMER_ENV: block
    :END:
    for the first viable Beamer setup in Org
,*** Thanks to everyone else                                        :B_block:
    :PROPERTIES:
    :BEAMER_COL: 0.48
    :BEAMER_ACT: <2->
    :BEAMER_ENV: block
    :END:
    for contributing to the discussion
,**** This will be formatted as a beamer note                       :B_note:
     :PROPERTIES:
     :BEAMER_env: note
     :END:
,** Frame 2 (where we will not use columns)
,*** Request
    Please test this stuff!
#+end_example

** HTML Export
:PROPERTIES:
:DESCRIPTION: Exporting to HTML.
:END:
#+cindex: HTML export

Org mode contains an HTML exporter with extensive HTML formatting
compatible with XHTML 1.0 strict standard.

*** HTML export commands
:PROPERTIES:
:DESCRIPTION: Invoking HTML export.
:END:

- {{{kbd(C-c C-e h h)}}} (~org-html-export-to-html~) ::
  #+kindex: C-c C-e h h
  #+kindex: C-c C-e h o
  #+findex: org-html-export-to-html

  Export as HTML file with a =.html= extension.  For =myfile.org=, Org
  exports to =myfile.html=, overwriting without warning.  {{{kbd(C-c
  C-e h o)}}} exports to HTML and opens it in a web browser.

- {{{kbd(C-c C-e h H)}}} (~org-html-export-as-html~) ::
  #+kindex: C-c C-e h H
  #+findex: org-html-export-as-html

  Exports to a temporary buffer.  Does not create a file.

*** HTML specific export settings
:PROPERTIES:
:DESCRIPTION: Settings for HTML export.
:END:

HTML export has a number of keywords, similar to the general options
settings described in [[*Export Settings]].

- =DESCRIPTION= ::

  #+cindex: @samp{DESCRIPTION}, keyword
  This is the document's description, which the HTML exporter inserts
  it as a HTML meta tag in the HTML file.  For long descriptions, use
  multiple =DESCRIPTION= lines.  The exporter takes care of wrapping
  the lines properly.

  The exporter includes a number of other meta tags, which can be customized
  by modifying ~org-html-meta-tags~.

- =HTML_DOCTYPE= ::

  #+cindex: @samp{HTML_DOCTYPE}, keyword
  #+vindex: org-html-doctype
  Specify the document type, for example: HTML5 (~org-html-doctype~).

- =HTML_CONTAINER= ::

  #+cindex: @samp{HTML_CONTAINER}, keyword
  #+vindex: org-html-container-element
  Specify the HTML container, such as =div=, for wrapping sections and
  elements (~org-html-container-element~).

- =HTML_LINK_HOME= ::

  #+cindex: @samp{HTML_LINK_HOME}, keyword
  #+vindex: org-html-link-home
  The URL for home link (~org-html-link-home~).

- =HTML_LINK_UP= ::

  #+cindex: @samp{HTML_LINK_UP}, keyword
  #+vindex: org-html-link-up
  The URL for the up link of exported HTML pages (~org-html-link-up~).

- =HTML_MATHJAX= ::

  #+cindex: @samp{HTML_MATHJAX}, keyword
  #+vindex: org-html-mathjax-options
  Options for MathJax (~org-html-mathjax-options~).  MathJax is used
  to typeset LaTeX math in HTML documents.  See [[*Math formatting in
  HTML export]], for an example.

- =HTML_HEAD= ::

  #+cindex: @samp{HTML_HEAD}, keyword
  #+vindex: org-html-head
  Arbitrary lines for appending to the HTML document's head
  (~org-html-head~).

- =HTML_HEAD_EXTRA= ::

  #+cindex: @samp{HTML_HEAD_EXTRA}, keyword
  #+vindex: org-html-head-extra
  More arbitrary lines for appending to the HTML document's head
  (~org-html-head-extra~).

- =KEYWORDS= ::

  #+cindex: @samp{KEYWORDS}, keyword
  Keywords to describe the document's content.  HTML exporter inserts
  these keywords as HTML meta tags.  For long keywords, use multiple
  =KEYWORDS= lines.

- =LATEX_HEADER= ::

  #+cindex: @samp{LATEX_HEADER}, keyword
  Arbitrary lines for appending to the preamble; HTML exporter appends
  when transcoding LaTeX fragments to images (see [[*Math formatting in
  HTML export]]).

- =SUBTITLE= ::

  #+cindex: @samp{SUBTITLE}, keyword
  The document's subtitle.  HTML exporter formats subtitle if document
  type is =HTML5= and the CSS has a =subtitle= class.

Some of these keywords are explained in more detail in the following
sections of the manual.

*** HTML doctypes
:PROPERTIES:
:DESCRIPTION: Exporting various (X)HTML flavors.
:END:

Org can export to various (X)HTML flavors.

#+vindex: org-html-doctype
#+vindex: org-html-doctype-alist
Set the ~org-html-doctype~ variable for different (X)HTML variants.
Depending on the variant, the HTML exporter adjusts the syntax of HTML
conversion accordingly.  Org includes the following ready-made
variants:

- ~"html4-strict"~
- ~"html4-transitional"~
- ~"html4-frameset"~
- ~"xhtml-strict"~
- ~"xhtml-transitional"~
- ~"xhtml-frameset"~
- ~"xhtml-11"~
- ~"html5"~
- ~"xhtml5"~

#+texinfo: @noindent
See the variable ~org-html-doctype-alist~ for details.  The default is
~"xhtml-strict"~.

#+vindex: org-html-html5-fancy
#+cindex: @samp{HTML5}, export new elements
Org's HTML exporter does not by default enable new block elements
introduced with the HTML5 standard.  To enable them, set
~org-html-html5-fancy~ to non-~nil~.  Or use an =OPTIONS= line in the
file to set =html5-fancy=.

HTML5 documents can now have arbitrary =#+BEGIN= ... =#+END= blocks.
For example:

#+begin_example
,#+BEGIN_aside
  Lorem ipsum
,#+END_aside
#+end_example

#+texinfo: @noindent
exports to:

#+begin_src html
<aside>
  <p>Lorem ipsum</p>
</aside>
#+end_src

#+texinfo: @noindent
while this:

#+begin_example
,#+ATTR_HTML: :controls controls :width 350
,#+BEGIN_video
,#+HTML: <source src="movie.mp4" type="video/mp4">
,#+HTML: <source src="movie.ogg" type="video/ogg">
Your browser does not support the video tag.
,#+END_video
#+end_example

#+texinfo: @noindent
exports to:

#+begin_src html
<video controls="controls" width="350">
  <source src="movie.mp4" type="video/mp4">
  <source src="movie.ogg" type="video/ogg">
  <p>Your browser does not support the video tag.</p>
</video>
#+end_src

#+vindex: org-html-html5-elements
When special blocks do not have a corresponding HTML5 element, the
HTML exporter reverts to standard translation (see
~org-html-html5-elements~).  For example, =#+BEGIN_lederhosen= exports
to ~<div class="lederhosen">~.

Special blocks cannot have headlines.  For the HTML exporter to wrap
the headline and its contents in ~<section>~ or ~<article>~ tags, set
the =HTML_CONTAINER= property for the headline.

*** HTML preamble and postamble
:PROPERTIES:
:DESCRIPTION: Inserting preamble and postamble.
:END:
#+vindex: org-html-preamble
#+vindex: org-html-postamble
#+vindex: org-html-preamble-format
#+vindex: org-html-postamble-format
#+vindex: org-html-validation-link
#+vindex: org-export-creator-string
#+vindex: org-export-time-stamp-file

The HTML exporter has delineations for preamble and postamble.  The
default value for ~org-html-preamble~ is ~t~, which makes the HTML
exporter insert the preamble.  See the variable
~org-html-preamble-format~ for the format string.

Set ~org-html-preamble~ to a string to override the default format
string.  If set to a function, the HTML exporter expects the function
to return a string upon execution.  The HTML exporter inserts this
string in the preamble.  The HTML exporter does not insert a preamble
if ~org-html-preamble~ is set ~nil~.

The above also applies to ~org-html-postamble~ and
~org-html-postamble-format~.  In addition, ~org-html-postamble~ can be
set to ~auto~ (its default value), which makes the HTML exporter build
a postamble from looking up author's name, email address, creator's
name, and date.


*** Quoting HTML tags
:PROPERTIES:
:DESCRIPTION: Using direct HTML in Org files.
:END:

The HTML export back-end transforms =<= and =>= to =&lt;= and =&gt;=.
To include raw HTML code in the Org file so the HTML export back-end
can insert that HTML code in the output, use this inline syntax:
=@@html:...@@=.  For example:

: @@html:<b>@@bold text@@html:</b>@@

#+cindex: @samp{HTML}, keyword
#+cindex: @samp{BEGIN_EXPORT html}
For larger raw HTML code blocks, use these HTML export code blocks:

#+begin_example
,#+HTML: Literal HTML code for export

,#+BEGIN_EXPORT html
  All lines between these markers are exported literally
,#+END_EXPORT
#+end_example

*** Headlines in HTML export
:PROPERTIES:
:DESCRIPTION: Formatting headlines.
:END:
#+cindex: headlines, in HTML export

Headlines are exported to =<h1>=, =<h2>=, etc.  Each headline gets the
=id= attribute from =CUSTOM_ID= property, or a unique generated value,
see [[*Internal Links]].

#+vindex: org-html-self-link-headlines
When ~org-html-self-link-headlines~ is set to a non-~nil~ value, the
text of the headlines is also wrapped in =<a>= tags.  These tags have
a =href= attribute making the headlines link to themselves.

*** Links in HTML export
:PROPERTIES:
:DESCRIPTION: Inserting and formatting links.
:END:
#+cindex: links, in HTML export
#+cindex: internal links, in HTML export
#+cindex: external links, in HTML export

The HTML export back-end transforms Org's internal links (see
[[*Internal Links]]) to equivalent HTML links in the output.  The back-end
similarly handles Org's automatic links created by radio targets (see
[[*Radio Targets]]) similarly.  For Org links to external files, the
back-end transforms the links to /relative/ paths.

#+vindex: org-html-link-org-files-as-html
For Org links to other =.org= files, the back-end automatically
changes the file extension to =.html= and makes file paths relative.
If the =.org= files have an equivalent =.html= version at the same
location, then the converted links should work without any further
manual intervention.  However, to disable this automatic path
translation, set ~org-html-link-org-files-as-html~ to ~nil~.  When
disabled, the HTML export back-end substitutes the ID-based links in
the HTML output.  For more about linking files when publishing to
a directory, see [[*Publishing links]].

Org files can also have special directives to the HTML export
back-end.  For example, by using =#+ATTR_HTML= lines to specify new
format attributes to ~<a>~ or ~<img>~ tags.  This example shows
changing the link's title and style:

#+cindex: @samp{ATTR_HTML}, keyword
#+begin_example
,#+ATTR_HTML: :title The Org mode website :style color:red;
[[https://orgmode.org]]
#+end_example

*** Tables in HTML export
:PROPERTIES:
:DESCRIPTION: How to modify the formatting of tables.
:END:
#+cindex: tables, in HTML
#+vindex: org-export-html-table-tag

The HTML export back-end uses ~org-html-table-default-attributes~ when
exporting Org tables to HTML.  By default, the exporter does not draw
frames and cell borders.  To change for this for a table, use the
following lines before the table in the Org file:

#+cindex: @samp{CAPTION}, keyword
#+cindex: @samp{ATTR_HTML}, keyword
#+begin_example
,#+CAPTION: This is a table with lines around and between cells
,#+ATTR_HTML: :border 2 :rules all :frame border
#+end_example

The HTML export back-end preserves column groupings in Org tables (see
[[*Column Groups]]) when exporting to HTML.

Additional options for customizing tables for HTML export.

- ~org-html-table-align-individual-fields~ ::

  #+vindex: org-html-table-align-individual-fields
  Non-~nil~ attaches style attributes for alignment to each table
  field.

- ~org-html-table-caption-above~ ::

  #+vindex: org-html-table-caption-above
  Non-~nil~ places caption string at the beginning of the table.

- ~org-html-table-data-tags~ ::

  #+vindex: org-html-table-data-tags
  Opening and ending tags for table data fields.

- ~org-html-table-default-attributes~ ::

  #+vindex: org-html-table-default-attributes
  Default attributes and values for table tags.

- ~org-html-table-header-tags~ ::

  #+vindex: org-html-table-header-tags
  Opening and ending tags for table's header fields.

- ~org-html-table-row-tags~ ::

  #+vindex: org-html-table-row-tags
  Opening and ending tags for table rows.

- ~org-html-table-use-header-tags-for-first-column~ ::

  #+vindex: org-html-table-use-header-tags-for-first-column
  Non-~nil~ formats column one in tables with header tags.

*** Images in HTML export
:PROPERTIES:
:DESCRIPTION: How to insert figures into HTML output.
:END:
#+cindex: images, inline in HTML
#+cindex: inlining images in HTML

The HTML export back-end has features to convert Org image links to
HTML inline images and HTML clickable image links.

#+vindex: org-html-inline-images
When the link in the Org file has no description, the HTML export
back-end by default in-lines that image.  For example:
=[[file:myimg.jpg]]= is in-lined, while =[[file:myimg.jpg][the image]]= links to the text,
=the image=.  For more details, see the variable
~org-html-inline-images~.

On the other hand, if the description part of the Org link is itself
another link, such as =file:= or =http:= URL pointing to an image, the
HTML export back-end in-lines this image and links to the main image.
This Org syntax enables the back-end to link low-resolution thumbnail
to the high-resolution version of the image, as shown in this example:

: [[file:highres.jpg][file:thumb.jpg]]

To change attributes of in-lined images, use =#+ATTR_HTML= lines in
the Org file.  This example shows realignment to right, and adds ~alt~
and ~title~ attributes in support of text viewers and modern web
accessibility standards.

#+cindex: @samp{CAPTION}, keyword
#+cindex: @samp{ATTR_HTML}, keyword
#+begin_example
,#+CAPTION: A black cat stalking a spider
,#+ATTR_HTML: :alt cat/spider image :title Action! :align right
[[./img/a.jpg]]
#+end_example

The HTML export back-end copies the =http= links from the Org file
as-is.

*** Math formatting in HTML export
:PROPERTIES:
:DESCRIPTION: Beautiful math also on the web.
:END:
#+cindex: MathJax
#+cindex: dvipng
#+cindex: dvisvgm
#+cindex: ImageMagick

#+vindex: org-html-mathjax-options~
LaTeX math snippets (see [[*LaTeX fragments]]) can be displayed in two
different ways on HTML pages.  The default is to use the
[[https://www.mathjax.org][MathJax]], which should work out of the box
with Org[fn:: By default, Org loads MathJax from
[[https://www.jsdelivr.com/][jsDelivr]], as recommended in
[[https://docs.mathjax.org/en/latest/web/start.html][Getting Started
with MathJax Components]].][fn:46].  Some MathJax display options can
be configured via ~org-html-mathjax-options~, or in the buffer.  For
example, with the following settings,

#+begin_example
,#+HTML_MATHJAX: align: left indent: 5em tagside: left
#+end_example

#+texinfo: @noindent
equation labels are displayed on the left margin and equations are
five em from the left margin.

#+vindex: org-html-mathjax-template
See the docstring of ~org-html-mathjax-options~ for all supported
variables.  The MathJax template can be configure via
~org-html-mathjax-template~.

If you prefer, you can also request that LaTeX fragments are processed
into small images that will be inserted into the browser page.  Before
the availability of MathJax, this was the default method for Org
files.  This method requires that the dvipng program, dvisvgm or
ImageMagick suite is available on your system.  You can still get this
processing with

: #+OPTIONS: tex:dvipng

: #+OPTIONS: tex:dvisvgm

#+texinfo: @noindent
or

: #+OPTIONS: tex:imagemagick

*** Text areas in HTML export
:PROPERTIES:
:DESCRIPTION: An alternate way to show an example.
:END:

#+cindex: text areas, in HTML
Before Org mode's Babel, one popular approach to publishing code in
HTML was by using =:textarea=.  The advantage of this approach was
that copying and pasting was built into browsers with simple
JavaScript commands.  Even editing before pasting was made simple.

The HTML export back-end can create such text areas.  It requires an
=#+ATTR_HTML= line as shown in the example below with the =:textarea=
option.  This must be followed by either an example or a source code
block.  Other Org block types do not honor the =:textarea= option.

By default, the HTML export back-end creates a text area 80 characters
wide and height just enough to fit the content.  Override these
defaults with =:width= and =:height= options on the =#+ATTR_HTML=
line.

#+begin_example
,#+ATTR_HTML: :textarea t :width 40
,#+BEGIN_EXAMPLE
  (defun org-xor (a b)
     "Exclusive or."
     (if a (not b) b))
,#+END_EXAMPLE
#+end_example

*** CSS support
:PROPERTIES:
:DESCRIPTION: Changing the appearance of the output.
:END:
#+cindex: CSS, for HTML export
#+cindex: HTML export, CSS

#+vindex: org-export-html-todo-kwd-class-prefix
#+vindex: org-export-html-tag-class-prefix
You can modify the CSS style definitions for the exported file.  The
HTML exporter assigns the following special CSS classes[fn:: If the
classes on TODO keywords and tags lead to conflicts, use the variables
~org-html-todo-kwd-class-prefix~ and ~org-html-tag-class-prefix~ to
make them unique.] to appropriate parts of the document---your style
specifications may change these, in addition to any of the standard
classes like for headlines, tables, etc.

| ~p.author~           | author information, including email                    |
| ~p.date~             | publishing date                                        |
| ~p.creator~          | creator info, about org mode version                   |
| ~.title~             | document title                                         |
| ~.subtitle~          | document subtitle                                      |
| ~.todo~              | TODO keywords, all not-done states                     |
| ~.done~              | the DONE keywords, all states that count as done       |
| ~.WAITING~           | each TODO keyword also uses a class named after itself |
| ~.timestamp~         | timestamp                                              |
| ~.timestamp-kwd~     | keyword associated with a timestamp, like =SCHEDULED=  |
| ~.timestamp-wrapper~ | span around keyword plus timestamp                     |
| ~.tag~               | tag in a headline                                      |
| ~._HOME~             | each tag uses itself as a class, "@" replaced by "_"   |
| ~.target~            | target for links                                       |
| ~.linenr~            | the line number in a code example                      |
| ~.code-highlighted~  | for highlighting referenced code lines                 |
| ~div.outline-N~      | div for outline level N (headline plus text)           |
| ~div.outline-text-N~ | extra div for text at outline level N                  |
| ~.section-number-N~  | section number in headlines, different for each level  |
| ~.figure-number~     | label like "Figure 1:"                                 |
| ~.table-number~      | label like "Table 1:"                                  |
| ~.listing-number~    | label like "Listing 1:"                                |
| ~div.figure~         | how to format an in-lined image                        |
| ~pre.src~            | formatted source code                                  |
| ~pre.example~        | normal example                                         |
| ~p.verse~            | verse paragraph                                        |
| ~div.footnotes~      | footnote section headline                              |
| ~p.footnote~         | footnote definition paragraph, containing a footnote   |
| ~.footref~           | a footnote reference number (always a <sup>)           |
| ~.footnum~           | footnote number in footnote definition (always <sup>)  |
| ~.org-svg~           | default class for a linked =.svg= image                |

#+vindex: org-html-style-default
#+vindex: org-html-head
#+vindex: org-html-head-extra
#+cindex: @samp{HTML_INCLUDE_STYLE}, keyword
The HTML export back-end includes a compact default style in each
exported HTML file.  To override the default style with another style,
use these keywords in the Org file.  They will replace the global
defaults the HTML exporter uses.

#+cindex: @samp{HTML_HEAD}, keyword
#+cindex: @samp{HTML_HEAD_EXTRA}, keyword
#+begin_example
,#+HTML_HEAD: <link rel="stylesheet" type="text/css" href="style1.css" />
,#+HTML_HEAD_EXTRA: <link rel="alternate stylesheet" type="text/css" href="style2.css" />
#+end_example

#+vindex: org-html-head-include-default-style
To just turn off the default style, customize
~org-html-head-include-default-style~ variable, or use this option
line in the Org file.

#+cindex: @samp{html-style}, @samp{OPTIONS} item
: #+OPTIONS: html-style:nil

For longer style definitions, either use several =HTML_HEAD= and
=HTML_HEAD_EXTRA= keywords, or use ~<style> ... </style>~ blocks
around them.  Both of these approaches can avoid referring to an
external file.

#+cindex: @samp{HTML_CONTAINER_CLASS}, property
#+cindex: @samp{HTML_HEADLINE_CLASS}, property
In order to add styles to a subtree, use the =HTML_CONTAINER_CLASS=
property to assign a class to the tree.  In order to specify CSS
styles for a particular headline, you can use the ID specified in
a =CUSTOM_ID= property.  You can also assign a specific class to
a headline with the =HTML_HEADLINE_CLASS= property.

Never change the ~org-html-style-default~ constant.  Instead use other
simpler ways of customizing as described above.

*** JavaScript supported display of web pages
:PROPERTIES:
:DESCRIPTION: Info and folding in a web browser.
:ALT_TITLE: JavaScript support
:END:

Sebastian Rose has written a JavaScript program especially designed to
allow two different ways of viewing HTML files created with Org.  One
is an /Info/-like mode where each section is displayed separately and
navigation can be done with the {{{kbd(n)}}} and {{{kbd(p)}}} keys, and some other
keys as well, press {{{kbd(?)}}} for an overview of the available keys.  The
second one has a /folding/ view, much like Org provides inside Emacs.
The script is available at https://orgmode.org/org-info.js and the
documentation at https://orgmode.org/worg/code/org-info-js/.  The
script is hosted on https://orgmode.org, but for reliability, prefer
installing it on your own web server.

To use this program, just add this line to the Org file:

#+cindex: @samp{INFOJS_OPT}, keyword
: #+INFOJS_OPT: view:info toc:nil

#+texinfo: @noindent
The HTML header now has the code needed to automatically invoke the
script.  For setting options, use the syntax from the above line for
options described below:

- =path:= ::

  The path to the script.  The default is to grab the script from
  [[https://orgmode.org/org-info.js]], but you might want to have a local
  copy and use a path like =../scripts/org-info.js=.

- =view:= ::

  Initial view when the website is first shown.  Possible values are:

  | =info=     | Info-like interface with one section per page          |
  | =overview= | Folding interface, initially showing only top-level    |
  | =content=  | Folding interface, starting with all headlines visible |
  | =showall=  | Folding interface, all headlines and text visible      |

- =sdepth:= ::

  Maximum headline level still considered as an independent section
  for info and folding modes.  The default is taken from
  ~org-export-headline-levels~, i.e., the =H= switch in =OPTIONS=.  If
  this is smaller than in ~org-export-headline-levels~, each
  info/folding section can still contain child headlines.

- =toc:= ::

  Should the table of contents /initially/ be visible?  Even when
  =nil=, you can always get to the "toc" with {{{kbd(i)}}}.

- =tdepth:= ::

  The depth of the table of contents.  The defaults are taken from the
  variables ~org-export-headline-levels~ and ~org-export-with-toc~.

- =ftoc:= ::

  Does the CSS of the page specify a fixed position for the "toc"?  If
  yes, the toc is displayed as a section.

- =ltoc:= ::

  Should there be short contents (children) in each section?  Make
  this =above= if the section should be above initial text.

- =mouse:= ::

  Headings are highlighted when the mouse is over them.  Should be
  =underline= (default) or a background color like =#cccccc=.

- =buttons:= ::

  Should view-toggle buttons be everywhere?  When =nil= (the default),
  only one such button is present.

#+vindex: org-infojs-options
#+vindex: org-export-html-use-infojs
You can choose default values for these options by customizing the
variable ~org-infojs-options~.  If you always want to apply the script
to your pages, configure the variable ~org-export-html-use-infojs~.

** LaTeX Export
:PROPERTIES:
:DESCRIPTION: Exporting to @LaTeX{} and processing to PDF.
:END:
#+cindex: @LaTeX{} export
#+cindex: PDF export

The LaTeX export back-end can handle complex documents, incorporate
standard or custom LaTeX document classes, generate documents using
alternate LaTeX engines, and produce fully linked PDF files with
indexes, bibliographies, and tables of contents, destined for
interactive online viewing or high-quality print publication.

While the details are covered in-depth in this section, here are some
quick references to variables for the impatient: for engines, see
~org-latex-compiler~; for build sequences, see
~org-latex-pdf-process~; for packages, see
~org-latex-default-packages-alist~ and ~org-latex-packages-alist~.

An important note about the LaTeX export back-end: it is sensitive to
blank lines in the Org document.  That's because LaTeX itself depends
on blank lines to tell apart syntactical elements, such as paragraphs.

*** LaTeX/PDF export commands
:PROPERTIES:
:DESCRIPTION: For producing @LaTeX{} and PDF documents.
:END:

- {{{kbd(C-c C-e l l)}}} (~org-latex-export-to-latex~) ::

  #+kindex: C-c C-e l l
  #+findex: org-latex-export-to-latex~
  Export to a LaTeX file with a =.tex= extension.  For =myfile.org=,
  Org exports to =myfile.tex=, overwriting without warning.

- {{{kbd(C-c C-e l L)}}} (~org-latex-export-as-latex~) ::

  #+kindex: C-c C-e l L
  #+findex: org-latex-export-as-latex
  Export to a temporary buffer.  Do not create a file.

- {{{kbd(C-c C-e l p)}}} (~org-latex-export-to-pdf~) ::

  #+kindex: C-c C-e l p
  #+findex: org-latex-export-to-pdf
  Export as LaTeX file and convert it to PDF file.

- {{{kbd(C-c C-e l o)}}} ::

  #+kindex: C-c C-e l o
  Export as LaTeX file and convert it to PDF, then open the PDF using
  the default viewer.

- {{{kbd(M-x org-export-region-as-latex)}}} ::

  Convert the region to LaTeX under the assumption that it was in Org
  mode syntax before.  This is a global command that can be invoked in
  any buffer.

#+vindex: org-latex-compiler
#+vindex: org-latex-bibtex-compiler
#+vindex: org-latex-default-packages-alist
#+cindex: pdflatex
#+cindex: xelatex
#+cindex: lualatex
#+cindex: @samp{LATEX_COMPILER}, keyword
The LaTeX export back-end can use any of these LaTeX engines:
=pdflatex=, =xelatex=, and =lualatex=.  These engines compile LaTeX
files with different compilers, packages, and output options.  The
LaTeX export back-end finds the compiler version to use from
~org-latex-compiler~ variable or the =#+LATEX_COMPILER= keyword in the
Org file.  See the docstring for the
~org-latex-default-packages-alist~ for loading packages with certain
compilers.  Also see ~org-latex-bibtex-compiler~ to set the
bibliography compiler[fn:47].

*** LaTeX specific export settings
:PROPERTIES:
:DESCRIPTION: Unique to this @LaTeX{} back-end.
:END:

The LaTeX export back-end has several additional keywords for
customizing LaTeX output.  Setting these keywords works similar to the
general options (see [[*Export Settings]]).

#+attr_texinfo: :sep ,
- =DESCRIPTION= ::
  #+cindex: @samp{DESCRIPTION}, keyword
  #+vindex: org-latex-hyperref-template
  #+vindex: org-latex-title-command
  The document's description.  The description along with author name,
  keywords, and related file metadata are inserted in the output file
  by the hyperref package.  See ~org-latex-hyperref-template~ for
  customizing metadata items.  See ~org-latex-title-command~ for
  typesetting description into the document's front matter.  Use
  multiple =DESCRIPTION= keywords for long descriptions.

- =LANGUAGE= ::
  #+cindex: @samp{LANGUAGE}, keyword
  #+vindex: org-latex-packages-alist
  #+vindex: org-latex-language-alist

  Language code of the primary document language.

  The list of language codes supported by Org is stored in the
  variable ~org-latex-language-alist~.

  In order to be effective, the =babel= or =polyglossia=
  packages---according to the LaTeX compiler used---must be loaded
  with the appropriate language as argument.  This can be accomplished
  by modifying the ~org-latex-packages-alist~ variable, e.g., with the
  following snippet (note that =polyglossia= does not work with
  pdfLaTeX):

  #+begin_src emacs-lisp
  (add-to-list 'org-latex-packages-alist
               '("AUTO" "babel" t ("pdflatex" "xelatex" "lualatex")))
  (add-to-list 'org-latex-packages-alist
               '("AUTO" "polyglossia" t ("xelatex" "lualatex")))
  #+end_src

- =LATEX_CLASS= ::

  #+cindex: @samp{LATEX_CLASS}, keyword
  #+vindex: org-latex-default-class
  #+vindex: org-latex-classes
  This is LaTeX document class, such as /article/, /report/, /book/,
  and so on, which contain predefined preamble and headline level
  mapping that the LaTeX export back-end needs.  The back-end reads
  the default class name from the ~org-latex-default-class~ variable.
  Org has /article/ as the default class.  A valid default class must
  be an element of ~org-latex-classes~.

- =LATEX_CLASS_OPTIONS= ::

  #+cindex: @samp{LATEX_CLASS_OPTIONS}, keyword
  Options the LaTeX export back-end uses when calling the LaTeX
  document class.

- =LATEX_COMPILER= ::

  #+cindex: @samp{LATEX_COMPILER}, keyword
  #+vindex: org-latex-compiler
  The compiler, such as =pdflatex=, =xelatex=, =lualatex=, for
  producing the PDF.  See ~org-latex-compiler~.

- =LATEX_HEADER=, =LATEX_HEADER_EXTRA= ::

  #+cindex: @samp{LATEX_HEADER}, keyword
  #+cindex: @samp{LATEX_HEADER_EXTRA}, keyword
  #+vindex: org-latex-classes
  Arbitrary lines to add to the document's preamble, before the
  hyperref settings.  See ~org-latex-classes~ for adjusting the
  structure and order of the LaTeX headers.

- =KEYWORDS= ::

  #+cindex: @samp{KEYWORDS}, keyword
  #+vindex: org-latex-hyperref-template
  #+vindex: org-latex-title-command
  The keywords for the document.  The description along with author
  name, keywords, and related file metadata are inserted in the output
  file by the hyperref package.  See ~org-latex-hyperref-template~ for
  customizing metadata items.  See ~org-latex-title-command~ for
  typesetting description into the document's front matter.  Use
  multiple =KEYWORDS= lines if necessary.

- =SUBTITLE= ::

  #+cindex: @samp{SUBTITLE}, keyword
  #+vindex: org-latex-subtitle-separate
  #+vindex: org-latex-subtitle-format
  The document's subtitle.  It is typeset as per
  ~org-latex-subtitle-format~.  If ~org-latex-subtitle-separate~ is
  non-~nil~, it is typed outside of the ~\title~ macro.  See
  ~org-latex-hyperref-template~ for customizing metadata items.  See
  ~org-latex-title-command~ for typesetting description into the
  document's front matter.

The following sections have further details.

*** LaTeX header and sectioning structure
:PROPERTIES:
:DESCRIPTION: Setting up the export file structure.
:ALT_TITLE: LaTeX header and sectioning
:END:
#+cindex: @LaTeX{} class
#+cindex: @LaTeX{} sectioning structure
#+cindex: @LaTeX{} header
#+cindex: header, for @LaTeX{} files
#+cindex: sectioning structure, for @LaTeX{} export

The LaTeX export back-end converts the first three of Org's outline
levels into LaTeX headlines.  The remaining Org levels are exported as
lists.  To change this globally for the cut-off point between levels
and lists, (see [[*Export Settings]]).

By default, the LaTeX export back-end uses the /article/ class.

#+vindex: org-latex-default-class
#+vindex: org-latex-classes
#+vindex: org-latex-default-packages-alist
#+vindex: org-latex-packages-alist
To change the default class globally, edit ~org-latex-default-class~.
To change the default class locally in an Org file, add option lines
=#+LATEX_CLASS: myclass=.  To change the default class for just a part
of the Org file, set a subtree property, =EXPORT_LATEX_CLASS=.  The
class name entered here must be valid member of ~org-latex-classes~.
This variable defines a header template for each class into which the
exporter splices the values of ~org-latex-default-packages-alist~ and
~org-latex-packages-alist~.  Use the same three variables to define
custom sectioning or custom classes.

#+cindex: @samp{LATEX_CLASS}, keyword
#+cindex: @samp{LATEX_CLASS_OPTIONS}, keyword
#+cindex: @samp{EXPORT_LATEX_CLASS}, property
#+cindex: @samp{EXPORT_LATEX_CLASS_OPTIONS}, property
The LaTeX export back-end sends the =LATEX_CLASS_OPTIONS= keyword and
=EXPORT_LATEX_CLASS_OPTIONS= property as options to the LaTeX
~\documentclass~ macro.  The options and the syntax for specifying
them, including enclosing them in square brackets, follow LaTeX
conventions.

: #+LATEX_CLASS_OPTIONS: [a4paper,11pt,twoside,twocolumn]

#+cindex: @samp{LATEX_HEADER}, keyword
#+cindex: @samp{LATEX_HEADER_EXTRA}, keyword
The LaTeX export back-end appends values from =LATEX_HEADER= and
=LATEX_HEADER_EXTRA= keywords to the LaTeX header.  The docstring for
~org-latex-classes~ explains in more detail.  Also note that LaTeX
export back-end does not append =LATEX_HEADER_EXTRA= to the header
when previewing LaTeX snippets (see [[*Previewing LaTeX fragments]]).

A sample Org file with the above headers:

#+begin_example
,#+LATEX_CLASS: article
,#+LATEX_CLASS_OPTIONS: [a4paper]
,#+LATEX_HEADER: \usepackage{xyz}

,* Headline 1
  some text
,* Headline 2
  some more text
#+end_example

#+cindex: @samp{LANGUAGE}, keyword
#+vindex: org-export-default-language
LaTeX packages =babel= or =polyglossia= can also be loaded in a
document.  The "AUTO" string will be replaced in both cases by the
appropriate value for the =LANGUAGE= keyword, if present in the
document, or by the value of ~org-export-default-language~.  Let's see
some examples in one or another case.

=Babel= accepts the classic syntax and (in addition) the new syntax
with the =\babelprovide= command to load the languages using the new
=INI= files procedure.  Keep in mind that there are a number of
languages that are only served in babel using =INI= files, so they
cannot be declared using the classic syntax, but only using the
=\babelprovide= command (see
https://mirrors.ctan.org/macros/latex/required/babel/base/babel.pdf).
Valid usage examples could be:

#+begin_example
,#+LATEX_HEADER: \usepackage[french,italian,AUTO]{babel}
#+end_example

where "AUTO" is the main language.  But it can also be loaded using
the =\babelprovide= command:

#+begin_example
,#+LATEX_HEADER: \usepackage[french,italian]{babel}
,#+LATEX_HEADER: \babelprovide[import, main]{AUTO}
#+end_example

=Polyglossia=, for this procedure to be effective, must be loaded
using the same =babel= classic syntax (but note that /this is not/
the actual polyglossia syntax).  For example, suppose a document
declares Polytonic Greek as the primary language, and French as the
secondary language.  In this case, it would be expressed as:

#+begin_example
,#+LANGUAGE: el-polyton
,#+LATEX_HEADER: \usepackage[french,AUTO]{polyglossia}
#+end_example

This would produce in LaTeX (with the actual =polyglossia= syntax):

#+begin_example
\usepackage{polyglossia}
\setmainlanguage[variant=polytonic]{greek}
\setotherlanguage{french}
#+end_example

*** Quoting LaTeX code
:PROPERTIES:
:DESCRIPTION: Incorporating literal @LaTeX{} code.
:END:

The LaTeX export back-end can insert any arbitrary LaTeX code, see
[[*Embedded LaTeX]].  There are three ways to embed such code in the Org
file and they all use different quoting syntax.

#+cindex: inline, in @LaTeX{} export
Inserting in-line quoted with @ symbols:

: Code embedded in-line @@latex:any arbitrary LaTeX code@@ in a paragraph.

#+cindex: @samp{LATEX}, keyword
Inserting as one or more keyword lines in the Org file:

: #+LATEX: any arbitrary LaTeX code

#+cindex: @samp{BEGIN_EXPORT latex}
Inserting as an export block in the Org file, where the back-end
exports any code between begin and end markers:

#+begin_example
,#+BEGIN_EXPORT latex
  any arbitrary LaTeX code
,#+END_EXPORT
#+end_example

*** Tables in LaTeX export
:PROPERTIES:
:DESCRIPTION: Options for exporting tables to @LaTeX{}.
:END:
#+cindex: tables, in @LaTeX{} export

The LaTeX export back-end can pass several LaTeX attributes for table
contents and layout.  Besides specifying a label (see [[*Internal Links]])
and a caption (see [[*Captions]]), the other valid LaTeX attributes
include:

#+attr_texinfo: :sep ,
- =:mode= ::

  #+vindex: org-latex-default-table-mode
  The LaTeX export back-end wraps the table differently depending on
  the mode for accurate rendering of math symbols.  Mode is either
  =table=, =math=, =inline-math=, =verbatim= or =tabbing=.

  For =math= or =inline-math= mode, LaTeX export back-end wraps the
  table in a math environment, but every cell in it is exported as-is.
  For =tabbing= the LaTeX tabbing environment is used and the correct
  tabbing delimiters =\>= are used.
  The LaTeX export back-end determines the default mode from
  ~org-latex-default-table-mode~.  The LaTeX export back-end merges
  contiguous tables in the same mode into a single environment.

- =:environment= ::

  #+vindex: org-latex-default-table-environment
  Set the default LaTeX table environment for the LaTeX export
  back-end to use when exporting Org tables.  Common LaTeX table
  environments are provided by these packages: tabularx, longtable,
  array, tabu, and bmatrix.  For packages, such as tabularx and tabu,
  or any newer replacements, include them in the
  ~org-latex-packages-alist~ variable so the LaTeX export back-end can
  insert the appropriate load package headers in the converted LaTeX
  file.  Look in the docstring for the ~org-latex-packages-alist~
  variable for configuring these packages for LaTeX snippet previews,
  if any.

- =:caption= ::

  Use =CAPTION= keyword to set a simple caption for a table (see
  [[*Captions]]).  For custom captions, use =:caption= attribute, which
  accepts raw LaTeX code.  =:caption= value overrides =CAPTION= value.

- =:float=, =:placement= ::

  The table environments by default are not floats in LaTeX.  To make
  them floating objects use =:float= with one of the following
  options: =t= (for a default =table= environment), =sideways= (for a
  =sidewaystable= environment), =multicolumn= (to span the table
  across multiple columns of a page in a =table*= environment) and
  =nil=.  In addition to these three values, =:float= can pass through
  any arbitrary value, for example a user-defined float type with the
  =float= LaTeX package.

  LaTeX floats can also have additional layout =:placement=
  attributes.  These are the usual =[h t b p ! H]= permissions
  specified in square brackets.  Note that for =:float sideways=
  tables, the LaTeX export back-end ignores =:placement= attributes.

- =:align=, =:font=, =:width= ::

  The LaTeX export back-end uses these attributes for regular tables
  to set their alignments, fonts, and widths.

- =:options= ::

  The =:options= attribute allows adding an optional argument with
  a list of various table options (between brackets in LaTeX export),
  since certain tabular environments, such as longtblr of the
  tabularray LaTeX package, provides this structure.  For example:
  =:options remark{Note}={note},remark{Source}={source}=.

- =:spread= ::

  When =:spread= is non-~nil~, the LaTeX export back-end spreads or
  shrinks the table by the =:width= for tabu and longtabu
  environments.  =:spread= has no effect if =:width= is not set.

- =:booktabs=, =:center=, =:rmlines= ::

  #+vindex: org-latex-tables-booktabs
  #+vindex: org-latex-tables-centered
  All three commands are toggles.  =:booktabs= brings in modern
  typesetting enhancements to regular tables.  The booktabs package
  has to be loaded through ~org-latex-packages-alist~.  =:center= is
  for centering the table.  =:rmlines= removes all but the very first
  horizontal line made of ASCII characters from "table.el" tables
  only.

- =:math-prefix=, =:math-suffix=, =:math-arguments= ::

  The LaTeX export back-end inserts =:math-prefix= string value in
  a math environment before the table.  The LaTeX export back-end
  inserts =:math-suffix= string value in a math environment after the
  table.  The LaTeX export back-end inserts =:math-arguments= string
  value between the macro name and the table's contents.
  =:math-arguments= comes in use for matrix macros that require more
  than one argument, such as =qbordermatrix=.

LaTeX table attributes help formatting tables for a wide range of
situations, such as matrix product or spanning multiple pages:

#+begin_example
,#+ATTR_LATEX: :environment longtable :align l|lp{3cm}r|l
| ... | ... |
| ... | ... |

,#+ATTR_LATEX: :mode math :environment bmatrix :math-suffix \times
| a | b |
| c | d |
,#+ATTR_LATEX: :mode math :environment bmatrix
| 1 | 2 |
| 3 | 4 |
#+end_example

Set the caption with the LaTeX command
=\bicaption{HeadingA}{HeadingB}=:

#+begin_example
,#+ATTR_LATEX: :caption \bicaption{HeadingA}{HeadingB}
| ... | ... |
| ... | ... |
#+end_example

*** Images in LaTeX export
:PROPERTIES:
:DESCRIPTION: How to insert figures into @LaTeX{} output.
:END:
#+cindex: images, inline in LaTeX
#+cindex: inlining images in LaTeX
#+cindex: @samp{ATTR_LATEX}, keyword

The LaTeX export back-end processes image links in Org files that do
not have descriptions, such as these links =[[file:img.jpg]]= or
=[[./img.jpg]]=, as direct image insertions in the final PDF output.  In
the PDF, they are no longer links but actual images embedded on the
page.  The LaTeX export back-end uses =\includegraphics= macro to
insert the image.  But for TikZ (https://sourceforge.net/projects/pgf/)
images, the back-end uses an ~\input~ macro wrapped within
a ~tikzpicture~ environment.

For specifying image =:width=, =:height=, =:scale= and other =:options=,
use this syntax:

#+begin_example
,#+ATTR_LATEX: :width 5cm :options angle=90
[[./img/sed-hr4049.pdf]]
#+end_example

A =:scale= attribute overrides both =:width= and =:height= attributes.

For custom commands for captions, use the =:caption= attribute.  It
overrides the default =#+CAPTION= value:

#+begin_example
,#+ATTR_LATEX: :caption \bicaption{HeadingA}{HeadingB}
[[./img/sed-hr4049.pdf]]
#+end_example

When captions follow the method as described in [[*Captions]], the LaTeX
export back-end wraps the picture in a floating =figure= environment.
To float an image without specifying a caption, set the =:float=
attribute to one of the following:

- =t= ::

  For a default =figure= environment.

- =multicolumn= ::

  To span the image across multiple columns of a page; the back-end
  wraps the image in a =figure*= environment.

- =wrap= ::

  For text to flow around the image on the right; the figure occupies
  the left half of the page.

- =sideways= ::

  For a new page with the image sideways, rotated ninety degrees, in
  a =sidewaysfigure= environment; overrides =:placement= setting.

- =nil= ::

  To avoid a =:float= even if using a caption.

- Any arbitrary value ::

  For example, a user-defined float type with the =float= LaTeX
  package.


Use the =placement= attribute to modify a floating environment's
placement.

#+begin_example
,#+ATTR_LATEX: :float wrap :width 0.38\textwidth :placement {r}{0.4\textwidth}
[[./img/hst.png]]
#+end_example

#+vindex: org-latex-images-centered
#+cindex: center image in LaTeX export
#+cindex: image, centering in LaTeX export
The LaTeX export back-end centers all images by default.  Setting
=:center= to =nil= disables centering.  To disable centering globally,
set ~org-latex-images-centered~ to =nil=.

Set the =:comment-include= attribute to non-~nil~ value for the LaTeX
export back-end to comment out the =\includegraphics= macro.

*** Plain lists in LaTeX export
:PROPERTIES:
:DESCRIPTION: Attributes specific to lists.
:END:

#+cindex: plain lists, in @LaTeX{} export
#+cindex: @samp{ATTR_LATEX}, keyword
The LaTeX export back-end accepts the =environment= and =options=
attributes for plain lists.  Both attributes work together for
customizing lists, as shown in the examples:

#+begin_example
,#+LATEX_HEADER: \usepackage[inline]{enumitem}
Some ways to say "Hello":
,#+ATTR_LATEX: :environment itemize*
,#+ATTR_LATEX: :options [label={}, itemjoin={,}, itemjoin*={, and}]
- Hola
- Bonjour
- Guten Tag.
#+end_example

Since LaTeX supports only four levels of nesting for lists, use an
external package, such as =enumitem= in LaTeX, for levels deeper than
four:

#+begin_example
,#+LATEX_HEADER: \usepackage{enumitem}
,#+LATEX_HEADER: \renewlist{itemize}{itemize}{9}
,#+LATEX_HEADER: \setlist[itemize]{label=$\circ$}
- One
  - Two
    - Three
      - Four
        - Five
#+end_example

*** Source blocks in LaTeX export
:PROPERTIES:
:DESCRIPTION: Attributes specific to source code blocks.
:END:
#+cindex: source blocks, in @LaTeX{} export
#+cindex: @samp{ATTR_LATEX}, keyword

The LaTeX export back-end can make source code blocks into floating
objects through the attributes =:float= and =:options=.  For =:float=:

- =t= ::

  Makes a source block float; by default floats any source block with
  a caption.

- =multicolumn= ::

  Spans the source block across multiple columns of a page.

- =nil= ::

  Avoids a =:float= even if using a caption; useful for source code
  blocks that may not fit on a page.

#+begin_example
,#+ATTR_LATEX: :float nil
,#+BEGIN_SRC emacs-lisp
  Lisp code that may not fit in a single page.
,#+END_SRC
#+end_example

#+vindex: org-latex-listings-options
#+vindex: org-latex-minted-options
#+vindex: org-latex-engraved-options
The LaTeX export back-end passes string values in =:options= to LaTeX
packages for customization of that specific source block.  In the
example below, the =:options= are set for Engraved or Minted.  Minted
is a source code highlighting LaTeX package with many configurable
options[fn:: Minted uses an external Python package for code
highlighting, which requires the flag =-shell-escape= to be added to
~org-latex-pdf-process~.].  Both Minted and Engraved are built on
[[https://www.ctan.org/pkg/fvextra][fvextra]], and so support many of
the same options.

#+begin_example
,#+ATTR_LATEX: :options mathescape
,#+BEGIN_SRC emacs-lisp
  (defun Fib (n) ; $n_i = n_{i-2} + n_{i-1}$
    (if (< n 2) n (+ (Fib (- n 1)) (Fib (- n 2)))))
,#+END_SRC
#+end_example

To apply similar configuration options for all source blocks in a
file, use the ~org-latex-listings-options~,
~org-latex-engraved-options~, and ~org-latex-minted-options~
variables.

*** Example blocks in LaTeX export
:PROPERTIES:
:DESCRIPTION: Attributes specific to example blocks.
:END:
#+cindex: example blocks, in @LaTeX{} export
#+cindex: verbatim blocks, in @LaTeX{} export
#+cindex: @samp{ATTR_LATEX}, keyword

The LaTeX export back-end wraps the contents of example blocks in
a =verbatim= environment.  To change this behavior to use another
environment globally, specify an appropriate export filter (see
[[*Advanced Export Configuration]]).  To change this behavior to use
another environment for each block, use the =:environment= parameter
to specify a custom environment.

#+begin_example
,#+ATTR_LATEX: :environment myverbatim
,#+BEGIN_EXAMPLE
  This sentence is false.
,#+END_EXAMPLE
#+end_example

*** Special blocks in LaTeX export
:PROPERTIES:
:DESCRIPTION: Attributes specific to special blocks.
:END:

#+cindex: special blocks, in @LaTeX{} export
#+cindex: abstract, in @LaTeX{} export
#+cindex: proof, in @LaTeX{} export
#+cindex: @samp{ATTR_LATEX}, keyword

For other special blocks in the Org file, the LaTeX export back-end
makes a special environment of the same name.  The back-end also takes
=:options=, if any, and appends as-is to that environment's opening
string.  For example:

#+begin_example
,#+BEGIN_abstract
  We demonstrate how to solve the Syracuse problem.
,#+END_abstract

,#+ATTR_LATEX: :options [Proof of important theorem]
,#+BEGIN_proof
  ...
  Therefore, any even number greater than 2 is the sum of two primes.
,#+END_proof
#+end_example

#+texinfo: @noindent
exports to

#+begin_example
\begin{abstract}
  We demonstrate how to solve the Syracuse problem.
\end{abstract}

\begin{proof}[Proof of important theorem]
  ...
  Therefore, any even number greater than 2 is the sum of two primes.
\end{proof}
#+end_example

If you need to insert a specific caption command, use =:caption=
attribute.  It overrides standard =CAPTION= value, if any.  For
example:

#+begin_example
,#+ATTR_LATEX: :caption \MyCaption{HeadingA}
,#+BEGIN_proof
  ...
,#+END_proof
#+end_example

*** Horizontal rules in LaTeX export
:PROPERTIES:
:DESCRIPTION: Attributes specific to horizontal rules.
:END:
#+cindex: horizontal rules, in @LaTeX{} export
#+cindex: @samp{ATTR_LATEX}, keyword

The LaTeX export back-end converts horizontal rules by the specified
=:width= and =:thickness= attributes.  For example:

#+begin_example
,#+ATTR_LATEX: :width .6\textwidth :thickness 0.8pt
-----
#+end_example

*** Verse blocks in LaTeX export
:PROPERTIES:
:DESCRIPTION: Attributes specific to special blocks.
:END:

#+cindex: verse blocks, in @LaTeX{} export
#+cindex: @samp{ATTR_LATEX}, keyword

The LaTeX export back-end accepts four attributes for verse blocks:
=:lines=, =:center=, =:versewidth= and =:latexcode=.  The three first
require the external LaTeX package =verse.sty=, which is an extension
of the standard LaTeX environment.

- =:lines= :: To add marginal verse numbering.  Its value is an
  integer, the sequence in which the verses should be numbered.
- =:center= :: With value =t= all the verses on the page are optically
  centered (a typographic convention for poetry), taking as a
  reference the longest verse, which must be indicated by the
  attribute =:versewidth=.
- =:versewidth= :: Its value is a literal text string with the longest
  verse.
- =:latexcode= :: It accepts any arbitrary LaTeX code that can be
  included within a LaTeX =verse= environment.

A complete example with Shakespeare's first sonnet:

#+begin_src org
,#+ATTR_LATEX: :center t :latexcode \color{red} :lines 5
,#+ATTR_LATEX: :versewidth Feed’st thy light’s flame with self-substantial fuel,
,#+BEGIN_VERSE
From fairest creatures we desire increase,
That thereby beauty’s rose might never die,
But as the riper should by time decease
His tender heir might bear his memory
But thou, contracted to thine own bright eyes,
Feed’st thy light’s flame with self-substantial fuel,
Making a famine where abundance lies,
Thyself thy foe, to thy sweet self too cruel.
Thou that art now the world’s fresh ornament,
And only herald to the gaudy spring,
Within thine own bud buriest thy content,
And, tender churl, mak’st waste in niggardly.
Pity the world, or else this glutton be,
To eat the world’s due, by the grave and thee.
,#+END_VERSE
#+end_src

*** Quote blocks in LaTeX export
:PROPERTIES:
:DESCRIPTION: Attributes specific to quote blocks.
:END:

#+cindex: quote blocks, in @LaTeX{} export
#+cindex: @samp{ATTR_LATEX}, keyword
#+cindex: org-latex-default-quote-environment

The LaTeX export back-end accepts two attributes for quote blocks:
=:environment=, for an arbitrary quoting environment (the default
value is that of ~org-latex-default-quote-environment~: ~"quote"~) and
=:options=.  For example, to choose the environment =quotation=,
included as an alternative to =quote= in standard LaTeX classes:

#+begin_example
,#+ATTR_LATEX: :environment quotation
,#+BEGIN_QUOTE
some text...
,#+END_QUOTE
#+end_example

To choose the =foreigndisplayquote= environment, included in the LaTeX
package =csquotes=, with the =german= option, use this syntax:

#+begin_example
,#+LATEX_HEADER:\usepackage[autostyle=true]{csquotes}
,#+ATTR_LATEX: :environment foreigndisplayquote :options {german}
,#+BEGIN_QUOTE
some text in German...
,#+END_QUOTE
#+end_example

#+texinfo: @noindent
which is exported to LaTeX as

#+begin_example
\begin{foreigndisplayquote}{german}
some text in German...
\end{foreigndisplayquote}
#+end_example

** Markdown Export
:PROPERTIES:
:DESCRIPTION: Exporting to Markdown.
:END:
#+cindex: Markdown export

The Markdown export back-end, "md", converts an Org file to Markdown
format, as defined at https://daringfireball.net/projects/markdown/.

Since it is built on top of the HTML back-end (see [[*HTML Export]]), it
converts every Org construct not defined in Markdown syntax, such as
tables, to HTML.

*** Markdown export commands
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- {{{kbd(C-c C-e m m)}}} (~org-md-export-to-markdown~) ::

  #+kindex: C-c C-c m m
  #+findex: org-md-export-to-markdown
  Export to a text file with Markdown syntax.  For =myfile.org=, Org
  exports to =myfile.md=, overwritten without warning.

- {{{kbd(C-c C-e m M)}}} (~org-md-export-as-markdown~) ::

  #+kindex: C-c C-c m M
  #+findex: org-md-export-as-markdown
  Export to a temporary buffer.  Does not create a file.

- {{{kbd(C-c C-e m o)}}} ::

  #+kindex: C-c C-e m o
  Export as a text file with Markdown syntax, then open it.

*** Header and sectioning structure
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+vindex: org-md-headline-style
Based on ~org-md-headline-style~, Markdown export can generate
headlines of both /atx/ and /setext/ types.  /atx/ limits headline
levels to two whereas /setext/ limits headline levels to six.  Beyond
these limits, the export back-end converts headlines to lists.  To set
a limit to a level before the absolute limit (see [[*Export Settings]]).

** OpenDocument Text Export
:PROPERTIES:
:DESCRIPTION: Exporting to OpenDocument Text.
:END:
#+cindex: ODT
#+cindex: OpenDocument
#+cindex: export, OpenDocument
#+cindex: LibreOffice

The ODT export back-end handles creating of OpenDocument Text (ODT)
format.  Documents created by this exporter use the
{{{cite(OpenDocument-v1.2 specification)}}}[fn:: See
[[https://docs.oasis-open.org/office/v1.2/OpenDocument-v1.2.html][Open
Document Format for Office Applications (OpenDocument) Version 1.2]].]
and are compatible with LibreOffice 3.4.

*** Pre-requisites for ODT export
:PROPERTIES:
:DESCRIPTION: Required packages.
:END:
#+cindex: zip

The ODT export back-end relies on the zip program to create the final
compressed ODT output.  Check if =zip= is locally available and
executable.  Without it, export cannot finish.

*** ODT export commands
:PROPERTIES:
:DESCRIPTION: Invoking export.
:END:

- {{{kbd(C-c C-e o o)}}} (~org-odt-export-to-odt~) ::

  #+kindex: C-c C-e o o
  #+findex: org-odt-export-to-odt
  Export as OpenDocument Text file.

  #+cindex: @samp{EXPORT_FILE_NAME}, property
  #+vindex: org-odt-preferred-output-format

  If ~org-odt-preferred-output-format~ is specified, the ODT export
  back-end automatically converts the exported file to that format.

  For =myfile.org=, Org exports to =myfile.odt=, overwriting without
  warning.  The ODT export back-end exports a region only if a region
  was active.

  If the selected region is a single tree, the ODT export back-end
  makes the tree head the document title.  Incidentally, {{{kbd(C-c
  @)}}} selects the current subtree.  If the tree head entry has, or
  inherits, an =EXPORT_FILE_NAME= property, the ODT export back-end
  uses that for file name.

- {{{kbd(C-c C-e o O)}}} ::

  #+kindex: C-c C-e o O
  Export as an OpenDocument Text file and open the resulting file.

  #+vindex: org-export-odt-preferred-output-format
  If ~org-export-odt-preferred-output-format~ is specified, open the
  converted file instead.  See [[*Automatically exporting to other
  formats]].

*** ODT specific export settings
:PROPERTIES:
:DESCRIPTION: Configuration options.
:END:

The ODT export back-end has several additional keywords for
customizing ODT output.  Setting these keywords works similar to the
general options (see [[*Export Settings]]).

- =DESCRIPTION= ::

  #+cindex: @samp{DESCRIPTION}, keyword
  This is the document's description, which the ODT export back-end
  inserts as document metadata.  For long descriptions, use multiple
  lines, prefixed with =DESCRIPTION=.

- =KEYWORDS= ::

  #+cindex: @samp{KEYWORDS}, keyword
  The keywords for the document.  The ODT export back-end inserts the
  description along with author name, keywords, and related file
  metadata as metadata in the output file.  Use multiple =KEYWORDS= if
  necessary.

- =ODT_STYLES_FILE= ::

  #+cindex: @samp{ODT_STYLES_FILE}, keyword
  #+vindex: org-odt-styles-file
  The ODT export back-end uses the ~org-odt-styles-file~ by default.
  See [[*Applying custom styles]] for details.

- =SUBTITLE= ::

  #+cindex: @samp{SUBTITLE}, keyword
  The document subtitle.

*** Extending ODT export
:PROPERTIES:
:DESCRIPTION: Producing DOC, PDF files.
:END:

The ODT export back-end can produce documents in other formats besides
ODT using a specialized ODT converter process.  Its common interface
works with popular converters to produce formats such as =doc=, or
convert a document from one format, say =csv=, to another format, say
=xls=.

#+cindex: @file{unoconv}
#+vindex: org-odt-convert-process
Customize ~org-odt-convert-process~ variable to point to =unoconv=,
which is the ODT's preferred converter.  Working installations of
LibreOffice would already have =unoconv= installed.  Alternatively,
other converters may be substituted here.  See [[*Configuring
a document converter]].

**** Automatically exporting to other formats
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+vindex: org-odt-preferred-output-format
If ODT format is just an intermediate step to get to other formats,
such as =doc=, =docx=, =rtf=, or =pdf=, etc., then extend the ODT
export back-end to directly produce that format.  Specify the final
format in the ~org-odt-preferred-output-format~ variable.  This is one
way to extend (see [[*ODT export commands]]).

**** Converting between document formats
:PROPERTIES:
:UNNUMBERED: notoc
:END:

The Org export back-end is made to be inter-operable with a wide range
of text document format converters.  Newer generation converters, such
as LibreOffice and Pandoc, can handle hundreds of formats at once.
Org provides a consistent interaction with whatever converter is
installed.  Here are some generic commands:

- {{{kbd(M-x org-odt-convert)}}} ::

  #+findex: org-odt-convert
  Convert an existing document from one format to another.  With
  a prefix argument, opens the newly produced file.

*** Applying custom styles
:PROPERTIES:
:DESCRIPTION: Styling the output.
:END:
#+cindex: styles, custom
#+cindex: template, custom

The ODT export back-end comes with many OpenDocument styles (see
[[*Working with OpenDocument style files]]).  To expand or further
customize these built-in style sheets, either edit the style sheets
directly or generate them using an application such as LibreOffice.
The example here shows creating a style using LibreOffice.

**** Applying custom styles: the easy way
:PROPERTIES:
:UNNUMBERED: notoc
:END:

1. Create a sample =example.org= file with settings as shown below,
   and export it to ODT format.

   : #+OPTIONS: H:10 num:t

2. Open the above =example.odt= using LibreOffice.  Use the /Stylist/
   to locate the target styles, which typically have the "Org" prefix.
   Open one, modify, and save as either OpenDocument Text (ODT) or
   OpenDocument Template (OTT) file.

3.
   #+vindex: org-odt-styles-file
   Customize the variable ~org-odt-styles-file~ and point it to the
   newly created file.  For additional configuration options, see
   [[x-overriding-factory-styles][Overriding factory styles]].

   #+cindex: @samp{ODT_STYLES_FILE}, keyword
   To apply an ODT style to a particular file, use the
   =ODT_STYLES_FILE= keyword as shown in the example below:

   : #+ODT_STYLES_FILE: "/path/to/example.ott"

   #+texinfo: @noindent
   or

   : #+ODT_STYLES_FILE: ("/path/to/file.ott" ("styles.xml" "image/hdr.png"))

**** Using third-party styles and templates
:PROPERTIES:
:UNNUMBERED: notoc
:END:

The ODT export back-end relies on many templates and style names.
Using third-party styles and templates can lead to mismatches.
Templates derived from built-in ODT templates and styles seem to have
fewer problems.

*** Links in ODT export
:PROPERTIES:
:DESCRIPTION: Handling and formatting links.
:END:
#+cindex: links, in ODT export

ODT exporter creates native cross-references for internal links.  It
creates Internet-style links for all other links.

A link with no description and pointing to a regular, un-itemized,
outline heading is replaced with a cross-reference and section number
of the heading.

A =\ref{label}=-style reference to an image, table etc., is replaced
with a cross-reference and sequence number of the labeled entity.  See
[[*Labels and captions in ODT export]].

*** Tables in ODT export
:PROPERTIES:
:DESCRIPTION: Org tables conversions.
:END:

#+cindex: tables, in ODT export

The ODT export back-end handles native Org mode tables (see [[*Tables]])
and simple =table.el= tables.  Complex =table.el= tables having column
or row spans are not supported.  Such tables are stripped from the
exported document.

By default, the ODT export back-end exports a table with top and
bottom frames and with ruled lines separating row and column groups
(see [[*Column Groups]]).  All tables are typeset to occupy the same
width.  The ODT export back-end honors any table alignments and
relative widths for columns (see [[*Column Width and Alignment]]).

Note that the ODT export back-end interprets column widths as weighted
ratios, the default weight being 1.

#+cindex: @samp{ATTR_ODT}, keyword
Specifying =:rel-width= property on an =ATTR_ODT= line controls the
width of the table.  For example:

#+begin_example
,#+ATTR_ODT: :rel-width 50
| Area/Month    |   Jan |   Feb |   Mar |   Sum |
|---------------+-------+-------+-------+-------|
| /             |     < |       |       |     < |
| <l13>         |  <r5> |  <r5> |  <r5> |  <r6> |
| North America |     1 |    21 |   926 |   948 |
| Middle East   |     6 |    75 |   844 |   925 |
| Asia Pacific  |     9 |    27 |   790 |   826 |
|---------------+-------+-------+-------+-------|
| Sum           |    16 |   123 |  2560 |  2699 |
#+end_example

On export, the above table takes 50% of text width area.  The exporter
sizes the columns in the ratio: 13:5:5:5:6.  The first column is
left-aligned and rest of the columns, right-aligned.  Vertical rules
separate the header and the last column.  Horizontal rules separate
the header and the last row.

For even more customization, create custom table styles and associate
them with a table using the =ATTR_ODT= keyword.  See [[*Customizing
tables in ODT export]].

*** Images in ODT export
:PROPERTIES:
:DESCRIPTION: Inserting images.
:END:
#+cindex: images, embedding in ODT
#+cindex: embedding images in ODT

**** Embedding images
:PROPERTIES:
:UNNUMBERED: notoc
:END:

The ODT export back-end processes image links in Org files that do not
have descriptions, such as these links =[[file:img.jpg]]= or =[[./img.jpg]]=,
as direct image insertions in the final output.  Either of these
examples works:

: [[file:img.png]]

: [[./img.png]]

**** Embedding clickable images
:PROPERTIES:
:UNNUMBERED: notoc
:END:

For clickable images, provide a link whose description is another link
to an image file.  For example, to embed an image
=org-mode-unicorn.png= which when clicked jumps to https://orgmode.org
website, do the following

: [[https://orgmode.org][./org-mode-unicorn.png]]

**** Sizing and scaling of embedded images
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: @samp{ATTR_ODT}, keyword

Control the size and scale of the embedded images with the =ATTR_ODT=
attribute.

#+cindex: identify, ImageMagick
#+vindex: org-odt-pixels-per-inch
The ODT export back-end starts with establishing the size of the image
in the final document.  The dimensions of this size are measured in
centimeters.  The back-end then queries the image file for its
dimensions measured in pixels.  For this measurement, the back-end
relies on ImageMagick's identify program or Emacs ~create-image~ and
~image-size~ API.  ImageMagick is the preferred choice for large file
sizes or frequent batch operations.  The back-end then converts the
pixel dimensions using ~org-odt-pixels-per-inch~ into the familiar 72
dpi or 96 dpi.  The default value for this is in
~display-pixels-per-inch~, which can be tweaked for better results
based on the capabilities of the output device.  Here are some common
image scaling operations:

- Explicitly size the image ::

  To embed =img.png= as a 10 cm x 10 cm image, do the following:

  #+begin_example
  ,#+ATTR_ODT: :width 10 :height 10
  [[./img.png]]
  #+end_example

- Scale the image ::

  To embed =img.png= at half its size, do the following:

  #+begin_example
  ,#+ATTR_ODT: :scale 0.5
  [[./img.png]]
  #+end_example

- Scale the image to a specific width ::

  To embed =img.png= with a width of 10 cm while retaining the
  original height:width ratio, do the following:

  #+begin_example
  ,#+ATTR_ODT: :width 10
  [[./img.png]]
  #+end_example

- Scale the image to a specific height ::

  To embed =img.png= with a height of 10 cm while retaining the
  original height:width ratio, do the following:

  #+begin_example
  ,#+ATTR_ODT: :height 10
  [[./img.png]]
  #+end_example

**** Anchoring of images
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: @samp{ATTR_ODT}, keyword
The ODT export back-end can anchor images to =as-char=, =paragraph=,
or =page=.  Set the preferred anchor using the =:anchor= property of
the =ATTR_ODT= line.

To create an image that is anchored to a page:

#+begin_example
,#+ATTR_ODT: :anchor page
[[./img.png]]
#+end_example

*** Math formatting in ODT export
:PROPERTIES:
:DESCRIPTION: Formatting @LaTeX{} fragments.
:END:

The ODT exporter has special support for handling math.

**** LaTeX math snippets
:PROPERTIES:
:DESCRIPTION: Embedding in @LaTeX{} format.
:END:

LaTeX math snippets (see [[*LaTeX fragments]]) can be embedded in the ODT
document in one of the following ways:

- MathML ::

  #+cindex: MathML
  Add this line to the Org file.  This option is activated on
  a per-file basis.

  : #+OPTIONS: tex:t

  With this option, LaTeX fragments are first converted into MathML
  fragments using an external LaTeX-to-MathML converter program.  The
  resulting MathML fragments are then embedded as an OpenDocument
  Formula in the exported document.

  #+vindex: org-latex-to-mathml-convert-command
  #+vindex: org-latex-to-mathml-jar-file
  You can specify the LaTeX-to-MathML converter by customizing the
  variables ~org-latex-to-mathml-convert-command~ and
  ~org-latex-to-mathml-jar-file~.

  If you prefer to use MathToWeb[fn:: See
  [[http://www.mathtoweb.com/cgi-bin/mathtoweb_home.pl][MathToWeb]].]
  as your converter, you can configure the above variables as shown
  below.

  #+begin_src emacs-lisp
  (setq org-latex-to-mathml-convert-command
        "java -jar %j -unicode -force -df %o %I"
        org-latex-to-mathml-jar-file
        "/path/to/mathtoweb.jar")
  #+end_src

  #+texinfo: @noindent
  or, to use LaTeX​ML[fn:: See [[https://dlmf.nist.gov/LaTeXML/]].]
  instead,

  #+begin_src emacs-lisp
  (setq org-latex-to-mathml-convert-command
        "latexmlmath \"%i\" --presentationmathml=%o")
  #+end_src

  To quickly verify the reliability of the LaTeX-to-MathML
  converter, use the following commands:

  - {{{kbd(M-x org-export-as-odf)}}} ::

    Convert a LaTeX math snippet to an OpenDocument formula (=.odf=)
    file.

  - {{{kbd(M-x org-export-as-odf-and-open)}}} ::

    Convert a LaTeX math snippet to an OpenDocument formula (=.odf=)
    file and open the formula file with the system-registered
    application.

- PNG images ::

  #+cindex: dvipng
  #+cindex: dvisvgm
  #+cindex: ImageMagick
  Add this line to the Org file.  This option is activated on
  a per-file basis.

  : #+OPTIONS: tex:dvipng

  : #+OPTIONS: tex:dvisvgm

  #+texinfo: @noindent
  or

  : #+OPTIONS: tex:imagemagick

  Under this option, LaTeX fragments are processed into PNG or SVG
  images and the resulting images are embedded in the exported
  document.  This method requires dvipng program, dvisvgm or
  ImageMagick programs.

**** MathML and OpenDocument formula files
:PROPERTIES:
:DESCRIPTION: Embedding in native format.
:END:

When embedding LaTeX math snippets in ODT documents is not reliable,
there is one more option to try.  Embed an equation by linking to its
MathML (=.mml=) source or its OpenDocument formula (=.odf=) file as
shown below:

: [[./equation.mml]]

#+texinfo: @noindent
or

: [[./equation.odf]]

*** Labels and captions in ODT export
:PROPERTIES:
:DESCRIPTION: Rendering objects.
:END:

ODT format handles labeling and captioning of objects based on their
types.  Inline images, tables, LaTeX fragments, and Math formulas are
numbered and captioned separately.  Each object also gets a unique
sequence number based on its order of first appearance in the Org
file.  Each category has its own sequence.  A caption is just a label
applied to these objects.

#+begin_example
,#+CAPTION: Bell curve
,#+NAME:   fig:SED-HR4049
[[./img/a.png]]
#+end_example

When rendered, it may show as follows in the exported document:

: Figure 2: Bell curve

#+vindex: org-odt-category-map-alist
To modify the category component of the caption, customize the option
~org-odt-category-map-alist~.  For example, to tag embedded images
with the string "Illustration" instead of the default string "Figure",
use the following setting:

#+begin_src emacs-lisp
(setq org-odt-category-map-alist
      '(("__Figure__" "Illustration" "value" "Figure" org-odt--enumerable-image-p)))
#+end_src

With the above modification, the previous example changes to:

: Illustration 2: Bell curve

*** Literal examples in ODT export
:PROPERTIES:
:DESCRIPTION: For source code and example blocks.
:END:

The ODT export back-end supports literal examples (see [[*Literal
Examples]]) with full fontification.  Internally, the ODT export
back-end relies on =htmlfontify.el= to generate the style definitions
needed for fancy listings.  The auto-generated styles get =OrgSrc=
prefix and inherit colors from the faces used by Emacs Font Lock
library for that source language.

#+vindex: org-odt-fontify-srcblocks
For custom fontification styles, customize the
~org-odt-create-custom-styles-for-srcblocks~ option.

#+vindex: org-odt-create-custom-styles-for-srcblocks
To turn off fontification of literal examples, customize the
~org-odt-fontify-srcblocks~ option.

*** Advanced topics in ODT export
:PROPERTIES:
:DESCRIPTION: For power users.
:END:

The ODT export back-end has extensive features useful for power users
and frequent uses of ODT formats.

**** Configuring a document converter
:PROPERTIES:
:DESCRIPTION: Registering a document converter.
:UNNUMBERED: notoc
:END:
#+cindex: convert
#+cindex: doc, docx, rtf
#+cindex: converter

The ODT export back-end works with popular converters with little or
no extra configuration.  See [[*Extending ODT export]].  The following is
for unsupported converters or tweaking existing defaults.

- Register the converter ::

  #+vindex: org-export-odt-convert-processes
  Add the name of the converter to the ~org-odt-convert-processes~
  variable.  Note that it also requires how the converter is invoked
  on the command line.  See the variable's docstring for details.

- Configure its capabilities ::

  #+vindex: org-export-odt-convert-capabilities
  Specify which formats the converter can handle by customizing the
  variable ~org-odt-convert-capabilities~.  Use the entry for the
  default values in this variable for configuring the new converter.
  Also see its docstring for details.

- Choose the converter ::

  #+vindex: org-export-odt-convert-process
  Select the newly added converter as the preferred one by customizing
  the option ~org-odt-convert-process~.

**** Working with OpenDocument style files
:PROPERTIES:
:DESCRIPTION: Exploring internals.
:UNNUMBERED: notoc
:END:
#+cindex: styles, custom
#+cindex: template, custom

This section explores the internals of the ODT exporter; the means by which
it produces styled documents; the use of automatic and custom OpenDocument
styles.

The ODT exporter relies on two files for generating its output.  These
files are bundled with the distribution under the directory pointed to
by the variable ~org-odt-styles-dir~.  The two files are:

- =OrgOdtStyles.xml= <<x-orgodtstyles-xml>> ::

  This file contributes to the =styles.xml= file of the final ODT
  document.  This file gets modified for the following purposes:

  1. To control outline numbering based on user settings;

  2. To add styles generated by =htmlfontify.el= for fontification of
     code blocks.

- =OrgOdtContentTemplate.xml= <<x-orgodtcontenttemplate-xml>> ::

  This file contributes to the =content.xml= file of the final ODT
  document.  The contents of the Org outline are inserted between the
  =<office:text>= ... =</office:text>= elements of this file.

  Apart from serving as a template file for the final =content.xml=,
  the file serves the following purposes:

  1. It contains automatic styles for formatting of tables which are
     referenced by the exporter;

  2. It contains =<text:sequence-decl>= ... =</text:sequence-decl>=
     elements that control numbering of tables, images, equations, and
     similar entities.

<<x-overriding-factory-styles>> The following two variables control
the location from where the ODT exporter picks up the custom styles
and content template files.  Customize these variables to override the
factory styles used by the exporter.

- ~org-odt-styles-file~ ::

  The ODT export back-end uses the file pointed to by this variable,
  such as =styles.xml=, for the final output.  It can take one of the
  following values:

  - =FILE.xml= ::

    Use this file instead of the default =styles.xml=

  - =FILE.odt= or =FILE.ott= ::

    Use the =styles.xml= contained in the specified OpenDocument
    Text or Template file

  - =FILE.odt= or =FILE.ott= and a subset of included files ::

    Use the =styles.xml= contained in the specified OpenDocument Text
    or Template file.  Additionally extract the specified member files
    and embed those within the final ODT document.

    Use this option if the =styles.xml= file references additional
    files like header and footer images.

  - ~nil~ ::

    Use the default =styles.xml=.

- ~org-odt-content-template-file~ ::

  Use this variable to specify the blank =content.xml= used in the
  final output.

**** Creating one-off styles
:PROPERTIES:
:DESCRIPTION: Customizing styles, highlighting...
:UNNUMBERED: notoc
:END:

The ODT export back-end can read embedded raw OpenDocument XML from
the Org file.  Such direct formatting is useful for one-off instances.

- Embedding ODT tags as part of regular text ::

  Enclose OpenDocument syntax in =@@odt:...@@= for inline markup.  For
  example, to highlight a region of text do the following:

  #+begin_example
  @@odt:<text:span text:style-name="Highlight">This is highlighted
  text</text:span>@@.  But this is regular text.
  #+end_example

  *Hint:* To see the above example in action, edit the =styles.xml=
  (see [[x-orgodtstyles-xml][Factory styles]]) and add a custom /Highlight/ style as shown
  below:

  #+begin_example
  <style:style style:name="Highlight" style:family="text">
    <style:text-properties fo:background-color="#ff0000"/>
  </style:style>
  #+end_example

- Embedding a one-line OpenDocument XML ::

  #+cindex: @samp{ODT}, keyword
  The ODT export back-end can read one-liner options with =#+ODT:= in
  the Org file.  For example, to force a page break:

  #+begin_example
  ,#+ODT: <text:p text:style-name="PageBreak"/>
  #+end_example

  *Hint:* To see the above example in action, edit your
  =styles.xml= (see [[x-orgodtstyles-xml][Factory styles]]) and add a custom =PageBreak=
  style as shown below.

  #+begin_example
  <style:style style:name="PageBreak" style:family="paragraph"
               style:parent-style-name="Text_20_body">
    <style:paragraph-properties fo:break-before="page"/>
  </style:style>
  #+end_example

- Embedding a block of OpenDocument XML ::

  The ODT export back-end can also read ODT export blocks for
  OpenDocument XML.  Such blocks use the =#+BEGIN_EXPORT odt=
  ... =#+END_EXPORT= constructs.

  For example, to create a one-off paragraph that uses bold text, do
  the following:

  #+begin_example
  ,#+BEGIN_EXPORT odt
    <text:p text:style-name="Text_20_body_20_bold">
    This paragraph is specially formatted and uses bold text.
    </text:p>
  ,#+END_EXPORT
  #+end_example

**** Customizing tables in ODT export
:PROPERTIES:
:DESCRIPTION: Defining table templates.
:UNNUMBERED: notoc
:END:
#+cindex: tables, in ODT export
#+cindex: @samp{ATTR_ODT}, keyword

Override the default table format by specifying a custom table style
with the =#+ATTR_ODT= line.  For a discussion on default formatting of
tables, see [[*Tables in ODT export]].

This feature closely mimics the way table templates are defined in the
OpenDocument-v1.2 specification[fn::
[[https://docs.oasis-open.org/office/v1.2/OpenDocument-v1.2.html][OpenDocument-v1.2
Specification]]].

#+vindex: org-odt-table-styles
For quick preview of this feature, install the settings below and export the
table that follows:

#+begin_src emacs-lisp
(setq org-export-odt-table-styles
      (append org-export-odt-table-styles
              '(("TableWithHeaderRowAndColumn" "Custom"
                 ((use-first-row-styles . t)
                  (use-first-column-styles . t)))
                ("TableWithFirstRowandLastRow" "Custom"
                 ((use-first-row-styles . t)
                  (use-last-row-styles . t))))))
#+end_src

#+begin_example
,#+ATTR_ODT: :style TableWithHeaderRowAndColumn
| Name  | Phone | Age |
| Peter |  1234 |  17 |
| Anna  |  4321 |  25 |
#+end_example

The example above used =Custom= template and installed two table
styles =TableWithHeaderRowAndColumn= and
=TableWithFirstRowandLastRow=.  *Important:* The OpenDocument styles
needed for producing the above template were pre-defined.  They are
available in the section marked =Custom Table Template= in
=OrgOdtContentTemplate.xml= (see [[x-orgodtcontenttemplate-xml][Factory styles]]).  For adding new
templates, define new styles there.

To use this feature proceed as follows:

1. Create a table template[fn:: See the =<table:table-template>=
   element of the OpenDocument-v1.2 specification.].

   A table template is set of =table-cell= and =paragraph= styles for
   each of the following table cell categories:

   - Body
   - First column
   - Last column
   - First row
   - Last row
   - Even row
   - Odd row
   - Even column
   - Odd Column

   The names for the above styles must be chosen based on the name of
   the table template using a well-defined convention.

   The naming convention is better illustrated with an example.  For
   a table template with the name =Custom=, the needed style names are
   listed in the following table.

   | Cell type    | Cell style                   | Paragraph style                   |
   |--------------+------------------------------+-----------------------------------|
   | Body         | =CustomTableCell=            | =CustomTableParagraph=            |
   | First column | =CustomFirstColumnTableCell= | =CustomFirstColumnTableParagraph= |
   | Last column  | =CustomLastColumnTableCell=  | =CustomLastColumnTableParagraph=  |
   | First row    | =CustomFirstRowTableCell=    | =CustomFirstRowTableParagraph=    |
   | Last row     | =CustomLastRowTableCell=     | =CustomLastRowTableParagraph=     |
   | Even row     | =CustomEvenRowTableCell=     | =CustomEvenRowTableParagraph=     |
   | Odd row      | =CustomOddRowTableCell=      | =CustomOddRowTableParagraph=      |
   | Even column  | =CustomEvenColumnTableCell=  | =CustomEvenColumnTableParagraph=  |
   | Odd column   | =CustomOddColumnTableCell=   | =CustomOddColumnTableParagraph=   |

   To create a table template with the name =Custom=, define the above
   styles in the =<office:automatic-styles>= ...
   =</office:automatic-styles>= element of the content template file
   (see [[x-orgodtcontenttemplate-xml][Factory styles]]).

2. Define a table style[fn:: See the attributes =table:template-name=,
   =table:use-first-row-styles=, =table:use-last-row-styles=,
   =table:use-first-column-styles=, =table:use-last-column-styles=,
   =table:use-banding-rows-styles=, and
   =table:use-banding-column-styles= of the =<table:table>= element in
   the OpenDocument-v1.2 specification.].

   #+vindex: org-odt-table-styles
   To define a table style, create an entry for the style in the
   variable ~org-odt-table-styles~ and specify the following:

   - the name of the table template created in step (1),
   - the set of cell styles in that template that are to be activated.

   For example, the entry below defines two different table styles
   =TableWithHeaderRowAndColumn= and =TableWithFirstRowandLastRow=
   based on the same template =Custom=.  The styles achieve their
   intended effect by selectively activating the individual cell
   styles in that template.

   #+begin_src emacs-lisp
   (setq org-export-odt-table-styles
         (append org-export-odt-table-styles
                 '(("TableWithHeaderRowAndColumn" "Custom"
                    ((use-first-row-styles . t)
                     (use-first-column-styles . t)))
                   ("TableWithFirstRowandLastRow" "Custom"
                    ((use-first-row-styles . t)
                     (use-last-row-styles . t))))))
   #+end_src

3. Associate a table with the table style.

   To do this, specify the table style created in step (2) as part of
   the =ATTR_ODT= line as shown below.

   #+begin_example
   ,#+ATTR_ODT: :style TableWithHeaderRowAndColumn
   | Name  | Phone | Age |
   | Peter |  1234 |  17 |
   | Anna  |  4321 |  25 |
   #+end_example

**** Validating OpenDocument XML
:PROPERTIES:
:DESCRIPTION: Debugging corrupted OpenDocument files.
:UNNUMBERED: notoc
:END:

Sometimes ODT format files may not open due to =.odt= file corruption.
To verify if such a file is corrupt, validate it against the
OpenDocument Relax NG Compact (RNC) syntax schema.  But first the
=.odt= files have to be decompressed using =zip=.  Note that =.odt=
files are ZIP archives: [[info:emacs::File Archives]].  The contents of
ODT files are in XML.  For general help with validation---and
schema-sensitive editing---of XML files: [[info:nxml-mode::Introduction]].

#+vindex: org-export-odt-schema-dir
Customize ~org-odt-schema-dir~ to point to a directory with
OpenDocument RNC files and the needed schema-locating rules.  The ODT
export back-end takes care of updating the
~rng-schema-locating-files~.

** Org Export
:PROPERTIES:
:DESCRIPTION: Exporting to Org.
:END:

#+cindex: Org export
/org/ export back-end creates a normalized version of the Org document
in current buffer.  The exporter evaluates Babel code (see [[*Evaluating
Code Blocks]]) and removes content specific to other back-ends.

*** Org export commands
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- {{{kbd(C-c C-e O o)}}} (~org-org-export-to-org~) ::

  #+kindex: C-c C-e O o
  #+findex: org-org-export-to-org
  Export as an Org file with a =.org= extension.  For =myfile.org=,
  Org exports to =myfile.org.org=, overwriting without warning.

- {{{kbd(C-c C-e O v)}}} (~~) ::

  #+kindex: C-c C-e O v
  Export to an Org file, then open it.

** Texinfo Export
:PROPERTIES:
:DESCRIPTION: Exporting to Texinfo.
:END:

*** Texinfo export commands
:PROPERTIES:
:DESCRIPTION: Invoking commands.
:END:

- {{{kbd(C-c C-e i t)}}} (~org-texinfo-export-to-texinfo~) ::

  #+kindex: C-c C-e i t
  #+findex: org-texinfo-export-to-texinfo
  Export as a Texinfo file with =.texi= extension.  For =myfile.org=,
  Org exports to =myfile.texi=, overwriting without warning.

- {{{kbd(C-c C-e i i)}}} (~org-texinfo-export-to-info~) ::

  #+kindex: C-c C-e i i
  #+findex: org-texinfo-export-to-info
  #+vindex: org-texinfo-info-process
  Export to Texinfo format first and then process it to make an Info
  file.  To generate other formats, such as DocBook, customize the
  ~org-texinfo-info-process~ variable.

*** Texinfo specific export settings
:PROPERTIES:
:DESCRIPTION: Setting the environment.
:END:

The Texinfo export back-end has several additional keywords for
customizing Texinfo output.  Setting these keywords works similar to
the general options (see [[*Export Settings]]).

- =SUBTITLE= ::

  #+cindex: @samp{SUBTITLE}, keyword
  The document subtitle.

- =SUBAUTHOR= ::

  #+cindex: @samp{SUBAUTHOR}, keyword
  Additional authors for the document.

- =TEXINFO_FILENAME= ::

  #+cindex: @samp{TEXINFO_FILENAME}, keyword
  The Texinfo filename.

- =TEXINFO_CLASS= ::

  #+cindex: @samp{TEXINFO_CLASS}, keyword
  #+vindex: org-texinfo-default-class
  The default document class (~org-texinfo-default-class~), which must
  be a member of ~org-texinfo-classes~.

- =TEXINFO_HEADER= ::

  #+cindex: @samp{TEXINFO_HEADER}, keyword
  Arbitrary lines inserted at the end of the header.

- =TEXINFO_POST_HEADER= ::

  #+cindex: @samp{TEXINFO_POST_HEADER}, keyword
  Arbitrary lines inserted after the end of the header.

- =TEXINFO_DIR_CATEGORY= ::

  #+cindex: @samp{TEXINFO_DIR_CATEGORY}, keyword
  The directory category of the document.

- =TEXINFO_DIR_TITLE= ::

  #+cindex: @samp{TEXINFO_DIR_TITLE}, keyword
  The directory title of the document.

- =TEXINFO_DIR_DESC= ::

  #+cindex: @samp{TEXINFO_DIR_DESC}, keyword
  The directory description of the document.

- =TEXINFO_PRINTED_TITLE= ::

  #+cindex: @samp{TEXINFO_PRINTED_TITLE}, keyword
  The printed title of the document.

*** Texinfo file header
:PROPERTIES:
:DESCRIPTION: Generating the header.
:END:

#+cindex: @samp{TEXINFO_FILENAME}, keyword
After creating the header for a Texinfo file, the Texinfo back-end
automatically generates a name and destination path for the Info file.
To override this default with a more sensible path and name, specify
the =TEXINFO_FILENAME= keyword.

#+vindex: org-texinfo-coding-system
#+cindex: @samp{TEXINFO_HEADER}, keyword
Along with the output's file name, the Texinfo header also contains
language details (see [[*Export Settings]]) and encoding system as set in
the ~org-texinfo-coding-system~ variable.  Insert =TEXINFO_HEADER=
keywords for each additional command in the header, for example:

: #+TEXINFO_HEADER: @synindex

#+cindex: @samp{TEXINFO_CLASS}, keyword
#+vindex: org-texinfo-classes
Instead of repeatedly installing the same set of commands, define
a class in ~org-texinfo-classes~ once, and then activate it in the
document by setting the =TEXINFO_CLASS= keyword to that class.

*** Texinfo title and copyright page
:PROPERTIES:
:DESCRIPTION: Creating preamble pages.
:END:

#+cindex: @samp{TEXINFO_PRINTED_TITLE}, keyword
The default template for hard copy output has a title page with
=TITLE= and =AUTHOR= keywords (see [[*Export Settings]]).  To replace the
regular title with something different for the printed version, use
the =TEXINFO_PRINTED_TITLE= and =SUBTITLE= keywords.  Both expect raw
Texinfo code for setting their values.

#+cindex: @samp{SUBAUTHOR}, keyword
If one =AUTHOR= line is not sufficient, add multiple =SUBAUTHOR=
keywords.  They have to be set in raw Texinfo code.

#+begin_example
,#+AUTHOR: Jane Smith
,#+SUBAUTHOR: John Doe
,#+TEXINFO_PRINTED_TITLE: This Long Title@@inlinefmt{tex,@*} Is Broken in @TeX{}
#+end_example

#+cindex: @samp{COPYING}, property
Copying material is defined in a dedicated headline with a non-~nil~
=COPYING= property.  The back-end inserts the contents within
a =@copying= command at the beginning of the document.  The heading
itself does not appear in the structure of the document.

Copyright information is printed on the back of the title page.

#+begin_example
,* Legalese
  :PROPERTIES:
  :COPYING: t
  :END:

  This is a short example of a complete Texinfo file, version 1.0.

  Copyright \copy 2016 Free Software Foundation, Inc.
#+end_example

*** Info directory file
:PROPERTIES:
:DESCRIPTION: Installing a manual in Info file hierarchy.
:END:

#+cindex: @samp{dir} file, in Texinfo export
#+cindex: Info directory file, in Texinfo export
#+cindex: @code{install-info}, in Texinfo export

#+cindex: @samp{TEXINFO_DIR_CATEGORY}, keyword
#+cindex: @samp{TEXINFO_DIR_TITLE}, keyword
#+cindex: @samp{TEXINFO_DIR_DESC}, keyword
The end result of the Texinfo export process is the creation of an
Info file.  This Info file's metadata has variables for category,
title, and description: =TEXINFO_DIR_CATEGORY=, =TEXINFO_DIR_TITLE=,
and =TEXINFO_DIR_DESC= keywords that establish where in the Info
hierarchy the file fits.

Here is an example that writes to the Info directory file:

#+begin_example
,#+TEXINFO_DIR_CATEGORY: Emacs
,#+TEXINFO_DIR_TITLE: Org Mode: (org)
,#+TEXINFO_DIR_DESC: Outline-based notes management and organizer
#+end_example

*** Headings and sectioning structure
:PROPERTIES:
:DESCRIPTION: Building document structure.
:END:

#+vindex: org-texinfo-classes
#+vindex: org-texinfo-default-class
#+cindex: @samp{TEXINFO_CLASS}, keyword
The Texinfo export back-end uses a pre-defined scheme to convert Org
headlines to equivalent Texinfo structuring commands.  A scheme like
this maps top-level headlines to numbered chapters tagged as
~@chapter~ and lower-level headlines to unnumbered chapters tagged as
~@unnumbered~.  To override such mappings to introduce ~@part~ or
other Texinfo structuring commands, define a new class in
~org-texinfo-classes~.  Activate the new class with the
=TEXINFO_CLASS= keyword.  When no new class is defined and activated,
the Texinfo export back-end defaults to the
~org-texinfo-default-class~.

If an Org headline's level has no associated Texinfo structuring
command, or is below a certain threshold (see [[*Export Settings]]), then
the Texinfo export back-end makes it into a list item.

#+cindex: @samp{APPENDIX}, property
The Texinfo export back-end makes any headline with a non-~nil~
=APPENDIX= property into an appendix.  This happens independent of the
Org headline level or the =TEXINFO_CLASS= keyword.

#+cindex: @samp{ALT_TITLE}, property
#+cindex: @samp{DESCRIPTION}, property
The Texinfo export back-end creates a menu entry after the Org
headline for each regular sectioning structure.  To override this with
a shorter menu entry, use the =ALT_TITLE= property (see [[*Table of
Contents]]).  Texinfo menu entries also have an option for a longer
=DESCRIPTION= property.  Here's an example that uses both to override
the default menu entry:

#+begin_example
,* Controlling Screen Display
  :PROPERTIES:
  :ALT_TITLE: Display
  :DESCRIPTION: Controlling Screen Display
  :END:
#+end_example

#+cindex: Top node, in Texinfo export
The text before the first headline belongs to the /Top/ node, i.e.,
the node in which a reader enters an Info manual.  As such, it is
expected not to appear in printed output generated from the =.texi=
file.  See [[info:texinfo::The Top Node]], for more information.

*** Indices
:PROPERTIES:
:DESCRIPTION: Creating indices.
:END:

#+cindex: @samp{CINDEX}, keyword
#+cindex: concept index, in Texinfo export
#+cindex: @samp{FINDEX}, keyword
#+cindex: function index, in Texinfo export
#+cindex: @samp{KINDEX}, keyword
#+cindex: keystroke index, in Texinfo export
#+cindex: @samp{PINDEX}, keyword
#+cindex: program index, in Texinfo export
#+cindex: @samp{TINDEX}, keyword
#+cindex: data type index, in Texinfo export
#+cindex: @samp{VINDEX}, keyword
#+cindex: variable index, in Texinfo export
The Texinfo export back-end recognizes these indexing keywords if used
in the Org file: =CINDEX=, =FINDEX=, =KINDEX=, =PINDEX=, =TINDEX= and
=VINDEX=.  Write their value as verbatim Texinfo code; in particular,
={=, =}= and =@= characters need to be escaped with =@= if they do not
belong to a Texinfo command.

: #+CINDEX: Defining indexing entries

#+cindex: @samp{INDEX}, property
For the back-end to generate an index entry for a headline, set the
=INDEX= property to =cp= or =vr=.  These abbreviations come from
Texinfo that stand for concept index and variable index.  The Texinfo
manual has abbreviations for all other kinds of indexes.  The back-end
exports the headline as an unnumbered chapter or section command, and
then inserts the index after its contents.

#+begin_example
,* Concept Index
  :PROPERTIES:
  :INDEX: cp
  :END:
#+end_example

*** Quoting Texinfo code
:PROPERTIES:
:DESCRIPTION: Incorporating literal Texinfo code.
:END:

Use any of the following three methods to insert or escape raw Texinfo
code:

#+cindex: @samp{TEXINFO}, keyword
#+cindex: @samp{BEGIN_EXPORT texinfo}
#+begin_example
Richard @@texinfo:@sc{@@Stallman@@texinfo:}@@ commence' GNU.

,#+TEXINFO: @need800
This paragraph is preceded by...

,#+BEGIN_EXPORT texinfo
  @auindex Johnson, Mark
  @auindex Lakoff, George
,#+END_EXPORT
#+end_example

*** Plain lists in Texinfo export
:PROPERTIES:
:DESCRIPTION: List attributes.
:END:

#+cindex: lettered lists, in Texinfo export
#+cindex: enum, Texinfo attribute
The Texinfo export back-end converts unordered and ordered lists in
the Org file using the default command =@itemize=.

Ordered lists are numbered when exported to Texinfo format.  Such
numbering obeys any counter (see [[*Plain Lists]]) in the first item of
the list.  The =:enum= attribute also let you start the list at a
specific number, or switch to a lettered list, as illustrated here:

#+begin_example
#+ATTR_TEXINFO: :enum A
1. Alpha
2. Bravo
3. Charlie
#+end_example

#+cindex: @samp{ATTR_TEXINFO}, keyword
#+cindex: two-column tables, in Texinfo export
#+cindex: table-type, Texinfo attribute
The Texinfo export back-end by default converts description lists in
the Org file using the default command =@table=, which results in
a table with two columns.  To change this behavior, set =:table-type=
attribute to either =ftable= or =vtable= value.  For more information,
see [[info:texinfo::Two-column Tables]].

#+vindex: org-texinfo-table-default-markup
#+cindex: indic, Texinfo attribute
The Texinfo export back-end by default also applies a text highlight
based on the defaults stored in ~org-texinfo-table-default-markup~.
To override the default highlight command, specify another one with
the =:indic= attribute.

#+cindex: multiple items in Texinfo lists
#+cindex: sep, Texinfo attribute
Org syntax is limited to one entry per list item.  Nevertheless, the
Texinfo export back-end can split that entry according to any text
provided through the =:sep= attribute.  Each part then becomes a new
entry in the first column of the table.

The following example illustrates all the attributes above:

#+begin_example
,#+ATTR_TEXINFO: :table-type vtable :sep , :indic asis
- foo, bar :: This is the common text for variables foo and bar.
#+end_example

#+texinfo: @noindent
becomes

#+begin_example
@vtable @asis
@item foo
@itemx bar
This is the common text for variables foo and bar.
@end table
#+end_example

The =:compact= attribute is an alternative to the =:sep= attribute,
which allows writing each entry on its own line.  If this attribute is
non-nil and an item in a description list has no body but is followed
by another item, then the second item is transcoded to =@itemx=.  This
example is transcoded to the same output as above.

#+begin_example
,#+ATTR_TEXINFO: :table-type vtable :indic asis :compact t
- foo ::
- bar ::
  This is the common text for variables foo and bar.
#+end_example

Support for this compact syntax can also be enabled for all lists in
a file using the =compact-itemx= export option, or globally using the
variable ~org-texinfo-compact-itemx~.

The Texinfo export back-end also supports two approaches to writing
Texinfo definition commands (see [[info:texinfo::Definition Commands]]).
One of them uses description lists and is described below, the other
relies on special blocks (see [[*Special blocks in Texinfo export]]).

Items in a description list in a Org file that begin with =Function:=
or certain other prefixes are converted using Texinfo definition
commands.  This works even if other items in the same list do not have
such a prefix; if necessary a single description list is converted
using multiple tables (such as =@vtable=) and definition commands
(such as =@defun=).

#+begin_example
- Function: org-texinfo-drawer drawer contents info ::
  Transcode a DRAWER element from Org to Texinfo.
#+end_example

#+texinfo: @noindent
becomes

#+begin_example
@defun org-texinfo-drawer drawer contents info ::
  Transcode a DRAWER element from Org to Texinfo.
@end defun
#+end_example

The recognized prefixes are =Command:=, =Function:=, =Macro:=,
=Special Form:=, =Variable:= and =User Option:=.  These are the same
prefixes that appear in the Info file for the respective definition
commands.  For example a =Function:= item in the Org file is converted
to a =@defun= command in the Texinfo file, which in turn is converted
to a definition prefixed with =-- Function:= in the Info file.

As a special case the prefix =Key:= is also recognized.  No Texinfo
definition command exists for key bindings and the output in Info
files also lacks the =Key:= prefix.  Even so this special case is
supported because it provides a convenient shorthand, as illustrated
here:

#+begin_example
- Key: C-c C-c (do-something) ::
  This command does something.

- User Option: do-something-somehow ::
  This option controls how exactly ~do-something~ does its thing.
#+end_example

#+texinfo: @noindent
becomes

#+begin_example
@table @asis
@item @kbd{C-c C-c} (@code{do-something})
@kindex C-c C-c
@findex do-something
This command does something.
@end table

@defopt do-something-somehow
This option controls how exactly @code{do-something} does its thing.
@end defopt
#+end_example

#+texinfo: @noindent
Command in parenthesis, as done above, is optional.

*** Tables in Texinfo export
:PROPERTIES:
:DESCRIPTION: Table attributes.
:END:

#+cindex: @samp{ATTR_TEXINFO}, keyword
When exporting tables, the Texinfo export back-end uses the widest
cell width in each column.  To override this and instead specify as
fractions of line length, use the =:columns= attribute.  See example
below.

#+begin_example
,#+ATTR_TEXINFO: :columns .5 .5
| a cell | another cell |
#+end_example

*** Images in Texinfo export
:PROPERTIES:
:DESCRIPTION: Image attributes.
:END:

#+cindex: @samp{ATTR_TEXINFO}, keyword
Insert a file link to the image in the Org file, and the Texinfo
export back-end inserts the image.  These links must have the usual
supported image extensions and no descriptions.  To scale the image,
use =:width= and =:height= attributes.  For alternate text, use =:alt=
and specify the text using Texinfo code, as shown in the example:

#+begin_example
,#+ATTR_TEXINFO: :width 1in :alt Alternate @i{text}
[[ridt.pdf]]
#+end_example

*** Quotations in Texinfo export
:PROPERTIES:
:DESCRIPTION: Quote block attributes.
:END:

#+cindex: @samp{ATTR_TEXINFO}, keyword
You can write the text of a quotation within a quote block (see
[[*Paragraphs]]).  You may also emphasize some text at the beginning of
the quotation with the =:tag= attribute.

#+begin_example
,#+ATTR_TEXINFO: :tag Warning
,#+BEGIN_QUOTE
Striking your thumb with a hammer may cause severe pain and discomfort.
,#+END_QUOTE
#+end_example

To specify the author of the quotation, use the =:author= attribute.

#+begin_example
,#+ATTR_TEXINFO: :author King Arthur
,#+BEGIN_QUOTE
The Lady of the Lake, her arm clad in the purest shimmering samite,
held aloft Excalibur from the bosom of the water, signifying by divine
providence that I, Arthur, was to carry Excalibur.  That is why I am
your king.
,#+END_QUOTE
#+end_example

*** Key bindings in Texinfo export
:PROPERTIES:
:DESCRIPTION: @@kbd Texinfo command.
:END:

Org does not provide any markup for key bindings that corresponds to
Texinfo's ~@kbd~ and ~@key~ commands.  One way to deal with this is to
fall back to code syntax.  =~C-x SPC~=, for example, is transcoded to
~@code{C-x SPC}~.

A better approach is to define and use an Org macro named ~kbd~.  To
make that easier the function ~org-texinfo-kbd-macro~ is provided,
which is intended to be used like this:

#+begin_example
,#+macro: kbd (eval (org-texinfo-kbd-macro $1))

Type {{{kbd(C-c SPC)}}}.
#+end_example

#+texinfo: @noindent
which becomes

#+begin_example
Type @kbd{C-c @key{SPC}}.
#+end_example

*** Special blocks in Texinfo export
:PROPERTIES:
:DESCRIPTION: Special block attributes.
:END:

The Texinfo export back-end supports two approaches to writing Texinfo
definition commands.  One of them is described here, the other in
[[*Plain lists in Texinfo export]].

#+cindex: @samp{ATTR_TEXINFO}, keyword

The Texinfo export back-end converts special blocks to commands with
the same name.  It also adds any =:options= attributes to the end of
the command, as shown in this example:

#+begin_example
,#+ATTR_TEXINFO: :options org-org-export-to-org ...
,#+BEGIN_defun
  A somewhat obsessive function name.
,#+END_defun
#+end_example

#+texinfo: @noindent
becomes

#+begin_example
@defun org-org-export-to-org ...
  A somewhat obsessive function name.
@end defun
#+end_example

*** A Texinfo example
:PROPERTIES:
:DESCRIPTION: Processing Org to Texinfo.
:END:

Here is a more detailed example Org file.  See
[[info:texinfo::GNU Sample Texts]] for an equivalent example using
Texinfo code.

#+begin_example
,#+TITLE: GNU Sample {{{version}}}
,#+SUBTITLE: for version {{{version}}}, {{{updated}}}
,#+AUTHOR: A.U. Thor
,#+EMAIL: bug-sample@gnu.org

,#+OPTIONS: ':t toc:t author:t email:t
,#+LANGUAGE: en

,#+MACRO: version 2.0
,#+MACRO: updated last updated 4 March 2014

,#+TEXINFO_FILENAME: sample.info
,#+TEXINFO_HEADER: @syncodeindex pg cp

,#+TEXINFO_DIR_CATEGORY: Texinfo documentation system
,#+TEXINFO_DIR_TITLE: sample: (sample)
,#+TEXINFO_DIR_DESC: Invoking sample

,#+TEXINFO_PRINTED_TITLE: GNU Sample

This manual is for GNU Sample (version {{{version}}},
{{{updated}}}).

,* Copying
  :PROPERTIES:
  :COPYING:  t
  :END:

  This manual is for GNU Sample (version {{{version}}},
  {{{updated}}}), which is an example in the Texinfo documentation.

  Copyright \copy 2016 Free Software Foundation, Inc.

  ,#+BEGIN_QUOTE
  Permission is granted to copy, distribute and/or modify this
  document under the terms of the GNU Free Documentation License,
  Version 1.3 or any later version published by the Free Software
  Foundation; with no Invariant Sections, with no Front-Cover Texts,
  and with no Back-Cover Texts.  A copy of the license is included in
  the section entitled "GNU Free Documentation License".
  ,#+END_QUOTE

,* Invoking sample

  ,#+PINDEX: sample
  ,#+CINDEX: invoking @command{sample}

  This is a sample manual.  There is no sample program to invoke, but
  if there were, you could see its basic usage and command line
  options here.

,* GNU Free Documentation License
  :PROPERTIES:
  :APPENDIX: t
  :END:

  ,#+INCLUDE: fdl.org

,* Index
  :PROPERTIES:
  :INDEX:    cp
  :END:
#+end_example

** iCalendar Export
:PROPERTIES:
:DESCRIPTION: Exporting to iCalendar.
:END:
#+cindex: iCalendar export

A large part of Org mode's interoperability success is its ability to
easily export to or import from external applications.  The iCalendar
export back-end takes calendar data from Org files and exports to the
standard iCalendar format.

#+vindex: org-icalendar-include-todo
#+vindex: org-icalendar-use-deadline
#+vindex: org-icalendar-use-scheduled
The iCalendar export back-end can also incorporate TODO entries based
on the configuration of the ~org-icalendar-include-todo~ variable.
The back-end exports plain timestamps as =VEVENT=, TODO items as
=VTODO=, and also create events from deadlines that are in non-TODO
items.  The back-end uses the deadlines and scheduling dates in Org
TODO items for setting the start and due dates for the iCalendar TODO
entry.  Consult the ~org-icalendar-use-deadline~ and
~org-icalendar-use-scheduled~ variables for more details.

#+vindex: org-icalendar-categories
#+vindex: org-icalendar-alarm-time
For tags on the headline, the iCalendar export back-end makes them
into iCalendar categories.  To tweak the inheritance of tags and TODO
states, configure the variable ~org-icalendar-categories~.  To assign
clock alarms based on time, configure the ~org-icalendar-alarm-time~
variable.

#+vindex: org-icalendar-store-UID
#+cindex: @samp{ID}, property
The iCalendar format standard requires globally unique identifier---or
UID---for each entry.  The iCalendar export back-end creates UIDs
during export.  To save a copy of the UID in the Org file set the
variable ~org-icalendar-store-UID~.  The back-end looks for the =ID=
property of the entry for re-using the same UID for subsequent
exports.

Since a single Org entry can result in multiple iCalendar
entries---timestamp, deadline, scheduled item, or TODO item---Org adds
prefixes to the UID, depending on which part of the Org entry
triggered the creation of the iCalendar entry.  Prefixing ensures UIDs
remains unique, yet enable synchronization programs trace the
connections.

- {{{kbd(C-c C-e c f)}}} (~org-icalendar-export-to-ics~) ::

  #+kindex: C-c C-e c f
  #+findex: org-icalendar-export-to-ics
  Create iCalendar entries from the current Org buffer and store them
  in the same directory, using a file extension =.ics=.

- {{{kbd(C-c C-e c a)}}} (~org-icalendar-export-agenda-files~) ::

  #+kindex: C-c C-e c a
  #+findex: org-icalendar-export-agenda-files
  Create iCalendar entries from Org files in ~org-agenda-files~ and
  store in a separate iCalendar file for each Org file.

- {{{kbd(C-c C-e c c)}}} (~org-icalendar-combine-agenda-files~) ::

  #+kindex: C-c C-e c c
  #+findex: org-icalendar-combine-agenda-files
  #+vindex: org-icalendar-combined-agenda-file
  Create a combined iCalendar file from Org files in
  ~org-agenda-files~ and write it to
  ~org-icalendar-combined-agenda-file~ file name.

#+cindex: @samp{SUMMARY}, property
#+cindex: @samp{DESCRIPTION}, property
#+cindex: @samp{LOCATION}, property
#+cindex: @samp{TIMEZONE}, property
#+cindex: @samp{CLASS}, property
The iCalendar export back-end includes =SUMMARY=, =DESCRIPTION=,
=LOCATION=, =TIMEZONE= and =CLASS= properties from the Org entries
when exporting.  To force the back-end to inherit the =LOCATION=,
=TIMEZONE= and =CLASS= properties, configure the
~org-use-property-inheritance~ variable.

#+vindex: org-icalendar-include-body
When Org entries do not have =SUMMARY=, =DESCRIPTION=, =LOCATION= and
=CLASS= properties, the iCalendar export back-end derives the summary
from the headline, and derives the description from the body of the
Org item.  The ~org-icalendar-include-body~ variable limits the
maximum number of characters of the content are turned into its
description.

The =TIMEZONE= property can be used to specify a per-entry time zone,
and is applied to any entry with timestamp information.  Time zones
should be specified as per the IANA time zone database format, e.g.,
=Asia/Almaty=.  Alternately, the property value can be =UTC=, to force
UTC time for this entry only.

The =CLASS= property can be used to specify a per-entry visibility
class or access restrictions, and is applied to any entry with class
information.  The iCalendar standard defines three visibility classes:
- =PUBLIC= :: The entry is publicly visible (this is the default).
- =CONFIDENTIAL= :: Only a limited group of clients get access to the
  event.
- =PRIVATE= :: The entry can be retrieved only by its owner.
The server should treat unknown class properties the same as
=PRIVATE=.

Exporting to iCalendar format depends in large part on the
capabilities of the destination application.  Some are more lenient
than others.  Consult the Org mode FAQ for advice on specific
applications.

** Other Built-in Back-ends
:PROPERTIES:
:DESCRIPTION: Exporting to a man page.
:END:

Other export back-ends included with Org are:

- =ox-man.el=: Export to a man page.

To activate such back-ends, either customize ~org-export-backends~ or
load directly with =(require 'ox-man)=.  On successful load, the
back-end adds new keys in the export dispatcher (see [[*The Export
Dispatcher]]).

Follow the comment section of such files, for example, =ox-man.el=,
for usage and configuration details.

** Advanced Export Configuration
:PROPERTIES:
:DESCRIPTION: Fine-tuning the export output.
:END:

*** Export hooks
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+vindex: org-export-before-processing-hook
#+vindex: org-export-before-parsing-hook
The export process executes two hooks before the actual exporting
begins.  The first hook, ~org-export-before-processing-hook~, runs
before any expansions of macros, Babel code, and include keywords in
the buffer.  The second hook, ~org-export-before-parsing-hook~, runs
before the buffer is parsed.

Functions added to these hooks are called with a single argument: the
export back-end actually used, as a symbol.  You may use them for
heavy duty structural modifications of the document.  For example, you
can remove every headline in the buffer during export like this:

#+begin_src emacs-lisp
(defun my-headline-removal (backend)
  "Remove all headlines in the current buffer.
BACKEND is the export back-end being used, as a symbol."
  (org-map-entries
   (lambda () (delete-region (point) (line-beginning-position 2)))))

(add-hook 'org-export-before-parsing-hook #'my-headline-removal)
#+end_src

*** Filters
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: Filters, exporting
Filters are lists of functions to be applied to certain parts for
a given back-end.  The output from the first function in the filter is
passed on to the next function in the filter.  The final output is the
output from the final function in the filter.

The Org export process has many filter sets applicable to different
types of objects, plain text, parse trees, export options, and final
output formats.  The filters are named after the element type or
object type: ~org-export-filter-TYPE-functions~, where {{{var(TYPE)}}}
is the type targeted by the filter.  Valid types are:

#+attr_texinfo: :columns 0.33 0.33 0.33
| body                | bold               | babel-call       |
| center-block        | clock              | code             |
| diary-sexp          | drawer             | dynamic-block    |
| entity              | example-block      | export-block     |
| export-snippet      | final-output       | fixed-width      |
| footnote-definition | footnote-reference | headline         |
| horizontal-rule     | inline-babel-call  | inline-src-block |
| inlinetask          | italic             | item             |
| keyword             | latex-environment  | latex-fragment   |
| line-break          | link               | node-property    |
| options             | paragraph          | parse-tree       |
| plain-list          | plain-text         | planning         |
| property-drawer     | quote-block        | radio-target     |
| section             | special-block      | src-block        |
| statistics-cookie   | strike-through     | subscript        |
| superscript         | table              | table-cell       |
| table-row           | target             | timestamp        |
| underline           | verbatim           | verse-block      |

Here is an example filter that replaces non-breaking spaces ~ ~ in the
Org buffer with =~= for the LaTeX back-end.

#+begin_src emacs-lisp
(defun my-latex-filter-nobreaks (text backend info)
  "Ensure \" \" are properly handled in LaTeX export."
  (when (org-export-derived-backend-p backend 'latex)
    (replace-regexp-in-string " " "~" text)))

(add-to-list 'org-export-filter-plain-text-functions
             'my-latex-filter-nobreaks)
#+end_src

A filter requires three arguments: the code to be transformed, the
name of the back-end, and some optional information about the export
process.  The third argument can be safely ignored.  Note the use of
~org-export-derived-backend-p~ predicate that tests for /latex/
back-end or any other back-end, such as /beamer/, derived from
/latex/.

*** Defining filters for individual files
:PROPERTIES:
:UNNUMBERED: notoc
:END:

The Org export can filter not just for back-ends, but also for
specific files through the =BIND= keyword.  Here is an example with
two filters; one removes brackets from time stamps, and the other
removes strike-through text.  The filter functions are defined in
a code block in the same Org file, which is a handy location for
debugging.

#+begin_example
,#+BIND: org-export-filter-timestamp-functions (tmp-f-timestamp)
,#+BIND: org-export-filter-strike-through-functions (tmp-f-strike-through)
,#+BEGIN_SRC emacs-lisp :exports results :results none
  (defun tmp-f-timestamp (s backend info)
    (replace-regexp-in-string "&[lg]t;\\|[][]" "" s))
  (defun tmp-f-strike-through (s backend info) "")
,#+END_SRC
#+end_example

*** Extending an existing back-end
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Some parts of the conversion process can be extended for certain
elements so as to introduce a new or revised translation.  That is how
the HTML export back-end was extended to handle Markdown format.  The
extensions work seamlessly so any aspect of filtering not done by the
extended back-end is handled by the original back-end.  Of all the
export customization in Org, extending is very powerful as it operates
at the parser level.

For this example, make the /ascii/ back-end display the language used
in a source code block.  Also make it display only when some attribute
is non-~nil~, like the following:

: #+ATTR_ASCII: :language t

Then extend ASCII back-end with a custom "my-ascii" back-end.

#+begin_src emacs-lisp
(defun my-ascii-src-block (src-block contents info)
  "Transcode a SRC-BLOCK element from Org to ASCII.
CONTENTS is nil.  INFO is a plist used as a communication
channel."
  (if (not (org-export-read-attribute :attr_ascii src-block :language))
      (org-export-with-backend 'ascii src-block contents info)
    (concat
     (format ",--[ %s ]--\n%s`----"
             (org-element-property :language src-block)
             (replace-regexp-in-string
              "^" "| "
              (org-element-normalize-string
               (org-export-format-code-default src-block info)))))))

(org-export-define-derived-backend 'my-ascii 'ascii
  :translate-alist '((src-block . my-ascii-src-block)))
#+end_src

The ~my-ascii-src-block~ function looks at the attribute above the
current element.  If not true, hands over to /ascii/ back-end.  If
true, which it is in this example, it creates a box around the code
and leaves room for the inserting a string for language.  The last
form creates the new back-end that springs to action only when
translating ~src-block~ type elements.

To use the newly defined back-end, evaluate the following from an Org
buffer:

#+begin_src emacs-lisp
(org-export-to-buffer 'my-ascii "*Org MY-ASCII Export*")
#+end_src

Further steps to consider would be an interactive function,
self-installing an item in the export dispatcher menu, and other
user-friendly improvements.

** Export in Foreign Buffers
:PROPERTIES:
:DESCRIPTION: Author tables and lists in Org syntax.
:END:

The export back-ends in Org often include commands to convert selected
regions.  A convenient feature of this in-place conversion is that the
exported output replaces the original source.  Here are such
functions:

- ~org-ascii-convert-region-to-ascii~ ::

  #+findex: org-ascii-convert-region-to-ascii
  Convert the selected region into ASCII.

- ~org-ascii-convert-region-to-utf8~ ::

  #+findex: org-ascii-convert-region-to-utf8
  Convert the selected region into UTF-8.

- ~org-html-convert-region-to-html~ ::

  #+findex: org-html-convert-region-to-html
  Convert the selected region into HTML.

- ~org-latex-convert-region-to-latex~ ::

  #+findex: org-latex-convert-region-to-latex
  Convert the selected region into LaTeX.

- ~org-texinfo-convert-region-to-texinfo~ ::

  #+findex: org-texinfo-convert-region-to-texinfo
  Convert the selected region into Texinfo.

- ~org-md-convert-region-to-md~ ::

  #+findex: org-md-convert-region-to-md
  Convert the selected region into Markdown.

In-place conversions are particularly handy for quick conversion of
tables and lists in foreign buffers.  For example, in an HTML buffer,
write a list in Org syntax, select it, and convert it to HTML with
{{{kbd(M-x org-html-convert-region-to-html)}}}.

*** Exporting to minimal HTML
:PROPERTIES:
:DESCRIPTION: Exporting HTML without CSS, Javascript, etc.
:ALT_TITLE: Bare HTML
:END:

If you want to output a minimal HTML file, with no CSS, no Javascript,
no preamble or postamble, here are the variable you would need to set:

#+vindex: org-html-head
#+vindex: org-html-head-extra
#+vindex: org-html-head-include-default-style
#+vindex: org-html-head-include-scripts
#+vindex: org-html-preamble
#+vindex: org-html-postamble
#+vindex: org-html-use-infojs
#+begin_src emacs-lisp
(setq org-html-head ""
      org-html-head-extra ""
      org-html-head-include-default-style nil
      org-html-head-include-scripts nil
      org-html-preamble nil
      org-html-postamble nil
      org-html-use-infojs nil)
#+end_src

* Publishing
:PROPERTIES:
:DESCRIPTION: Create a web site of linked Org files.
:END:
#+cindex: publishing

Org includes a publishing management system that allows you to
configure automatic HTML conversion of /projects/ composed of
interlinked Org files.  You can also configure Org to automatically
upload your exported HTML pages and related attachments, such as
images and source code files, to a web server.

You can also use Org to convert files into PDF, or even combine HTML
and PDF conversion so that files are available in both formats on the
server.

Publishing has been contributed to Org by David O'Toole.

** Configuration
:PROPERTIES:
:DESCRIPTION: Defining projects.
:END:
Publishing needs significant configuration to specify files,
destination and many other properties of a project.

*** The variable ~org-publish-project-alist~
:PROPERTIES:
:DESCRIPTION: The central configuration variable.
:ALT_TITLE: Project alist
:END:
#+cindex: projects, for publishing

#+vindex: org-publish-project-alist
Publishing is configured almost entirely through setting the value of
one variable, called ~org-publish-project-alist~.  Each element of the
list configures one project, and may be in one of the two following
forms:

#+begin_src emacs-lisp
("project-name" :property value :property value ...)
#+end_src

#+texinfo: @noindent
i.e., a well-formed property list with alternating keys and values,
or:

#+begin_src emacs-lisp
("project-name" :components ("project-name" "project-name" ...))
#+end_src

In both cases, projects are configured by specifying property values.
A project defines the set of files that are to be published, as well
as the publishing configuration to use when publishing those files.
When a project takes the second form listed above, the individual
members of the ~:components~ property are taken to be sub-projects,
which group together files requiring different publishing options.
When you publish such a "meta-project", all the components are also
published, in the sequence given.

*** Sources and destinations for files
:PROPERTIES:
:DESCRIPTION: From here to there.
:ALT_TITLE: Sources and destinations
:END:
#+cindex: directories, for publishing

Most properties are optional, but some should always be set.  In
particular, Org needs to know where to look for source files, and
where to put published files.

- ~:base-directory~ ::

  Directory containing publishing source files.

- ~:publishing-directory~ ::

  Directory where output files are published.  You can directly
  publish to a webserver using a file name syntax appropriate for the
  Emacs tramp package.  Or you can publish to a local directory and
  use external tools to upload your website (see [[*Uploading Files]]).

- ~:preparation-function~ ::

  Function or list of functions to be called before starting the
  publishing process, for example, to run =make= for updating files to
  be published.  Each preparation function is called with a single
  argument, the project property list.

- ~:completion-function~ ::

  Function or list of functions called after finishing the publishing
  process, for example, to change permissions of the resulting files.
  Each completion function is called with a single argument, the
  project property list.

*** Selecting files
:PROPERTIES:
:DESCRIPTION: What files are part of the project?
:END:
#+cindex: files, selecting for publishing

By default, all files with extension =.org= in the base directory are
considered part of the project.  This can be modified by setting the
following properties

- ~:base-extension~ ::

  Extension---without the dot---of source files.  This actually is
  a regular expression.  Set this to the symbol ~any~ if you want to
  get all files in ~:base-directory~, even without extension.

- ~:exclude~ ::

  Regular expression to match file names that should not be published,
  even though they have been selected on the basis of their extension.

- ~:include~ ::

  List of files to be included regardless of ~:base-extension~ and
  ~:exclude~.

- ~:recursive~ ::

  Non-~nil~ means, check base-directory recursively for files to
  publish.

*** Publishing action
:PROPERTIES:
:DESCRIPTION: Setting the function doing the publishing.
:END:
#+cindex: action, for publishing

Publishing means that a file is copied to the destination directory
and possibly transformed in the process.  The default transformation
is to export Org files as HTML files, and this is done by the function
~org-html-publish-to-html~ which calls the HTML exporter (see [[*HTML
Export]]).  But you can also publish your content as PDF files using
~org-latex-publish-to-pdf~, or as ASCII, Texinfo, etc., using the
corresponding functions.

If you want to publish the Org file as an =.org= file but with
/archived/, /commented/, and /tag-excluded/ trees removed, use
~org-org-publish-to-org~.  This produces =file.org= and puts it in the
publishing directory.  If you want a htmlized version of this file,
set the parameter ~:htmlized-source~ to ~t~.  It produces
=file.org.html= in the publishing directory[fn:: If the publishing
directory is the same as the source directory, =file.org= is exported
as =file.org.org=, so you probably do not want to do this.].

Other files like images only need to be copied to the publishing
destination; for this you can use ~org-publish-attachment~.  For
non-Org files, you always need to specify the publishing function:

- ~:publishing-function~ ::

  Function executing the publication of a file.  This may also be
  a list of functions, which are all called in turn.

- ~:htmlized-source~ ::

  Non-~nil~ means, publish htmlized source.

The function must accept three arguments: a property list containing
at least a ~:publishing-directory~ property, the name of the file to
be published, and the path to the publishing directory of the output
file.  It should take the specified file, make the necessary
transformation, if any, and place the result into the destination
folder.

*** Options for the exporters
:PROPERTIES:
:DESCRIPTION: Tweaking HTML/@LaTeX{} export.
:ALT_TITLE: Publishing options
:END:
#+cindex: options, for publishing
#+cindex: publishing options

The property list can be used to set many export options for the HTML
and LaTeX exporters.  In most cases, these properties correspond to
user variables in Org.  The table below lists these properties along
with the variable they belong to.  See the documentation string for
the respective variable for details.

#+vindex: org-publish-project-alist
When a property is given a value in ~org-publish-project-alist~, its
setting overrides the value of the corresponding user variable, if
any, during publishing.  Options set within a file (see [[*Export
Settings]]), however, override everything.

**** Generic properties
:PROPERTIES:
:UNNUMBERED: notoc
:END:

| ~:archived-trees~       | ~org-export-with-archived-trees~   |
| ~:exclude-tags~         | ~org-export-exclude-tags~          |
| ~:headline-levels~      | ~org-export-headline-levels~       |
| ~:language~             | ~org-export-default-language~      |
| ~:preserve-breaks~      | ~org-export-preserve-breaks~       |
| ~:section-numbers~      | ~org-export-with-section-numbers~  |
| ~:select-tags~          | ~org-export-select-tags~           |
| ~:with-author~          | ~org-export-with-author~           |
| ~:with-broken-links~    | ~org-export-with-broken-links~     |
| ~:with-clocks~          | ~org-export-with-clocks~           |
| ~:with-creator~         | ~org-export-with-creator~          |
| ~:with-date~            | ~org-export-with-date~             |
| ~:with-drawers~         | ~org-export-with-drawers~          |
| ~:with-email~           | ~org-export-with-email~            |
| ~:with-emphasize~       | ~org-export-with-emphasize~        |
| ~:with-fixed-width~     | ~org-export-with-fixed-width~      |
| ~:with-footnotes~       | ~org-export-with-footnotes~        |
| ~:with-latex~           | ~org-export-with-latex~            |
| ~:with-planning~        | ~org-export-with-planning~         |
| ~:with-priority~        | ~org-export-with-priority~         |
| ~:with-properties~      | ~org-export-with-properties~       |
| ~:with-special-strings~ | ~org-export-with-special-strings~  |
| ~:with-sub-superscript~ | ~org-export-with-sub-superscripts~ |
| ~:with-tables~          | ~org-export-with-tables~           |
| ~:with-tags~            | ~org-export-with-tags~             |
| ~:with-tasks~           | ~org-export-with-tasks~            |
| ~:with-timestamps~      | ~org-export-with-timestamps~       |
| ~:with-title~           | ~org-export-with-title~            |
| ~:with-toc~             | ~org-export-with-toc~              |
| ~:with-todo-keywords~   | ~org-export-with-todo-keywords~    |

**** ASCII specific properties
:PROPERTIES:
:UNNUMBERED: notoc
:END:

| ~:ascii-bullets~                       | ~org-ascii-bullets~                       |
| ~:ascii-caption-above~                 | ~org-ascii-caption-above~                 |
| ~:ascii-charset~                       | ~org-ascii-charset~                       |
| ~:ascii-global-margin~                 | ~org-ascii-global-margin~                 |
| ~:ascii-format-drawer-function~        | ~org-ascii-format-drawer-function~        |
| ~:ascii-format-inlinetask-function~    | ~org-ascii-format-inlinetask-function~    |
| ~:ascii-headline-spacing~              | ~org-ascii-headline-spacing~              |
| ~:ascii-indented-line-width~           | ~org-ascii-indented-line-width~           |
| ~:ascii-inlinetask-width~              | ~org-ascii-inlinetask-width~              |
| ~:ascii-inner-margin~                  | ~org-ascii-inner-margin~                  |
| ~:ascii-links-to-notes~                | ~org-ascii-links-to-notes~                |
| ~:ascii-list-margin~                   | ~org-ascii-list-margin~                   |
| ~:ascii-paragraph-spacing~             | ~org-ascii-paragraph-spacing~             |
| ~:ascii-quote-margin~                  | ~org-ascii-quote-margin~                  |
| ~:ascii-table-keep-all-vertical-lines~ | ~org-ascii-table-keep-all-vertical-lines~ |
| ~:ascii-table-use-ascii-art~           | ~org-ascii-table-use-ascii-art~           |
| ~:ascii-table-widen-columns~           | ~org-ascii-table-widen-columns~           |
| ~:ascii-text-width~                    | ~org-ascii-text-width~                    |
| ~:ascii-underline~                     | ~org-ascii-underline~                     |
| ~:ascii-verbatim-format~               | ~org-ascii-verbatim-format~               |

**** Beamer specific properties
:PROPERTIES:
:UNNUMBERED: notoc
:END:

| ~:beamer-theme~                 | ~org-beamer-theme~                 |
| ~:beamer-column-view-format~    | ~org-beamer-column-view-format~    |
| ~:beamer-environments-extra~    | ~org-beamer-environments-extra~    |
| ~:beamer-frame-default-options~ | ~org-beamer-frame-default-options~ |
| ~:beamer-outline-frame-options~ | ~org-beamer-outline-frame-options~ |
| ~:beamer-outline-frame-title~   | ~org-beamer-outline-frame-title~   |
| ~:beamer-subtitle-format~       | ~org-beamer-subtitle-format~       |

**** HTML specific properties
:PROPERTIES:
:UNNUMBERED: notoc
:END:

| ~:html-allow-name-attribute-in-anchors~        | ~org-html-allow-name-attribute-in-anchors~        |
| ~:html-checkbox-type~                          | ~org-html-checkbox-type~                          |
| ~:html-container~                              | ~org-html-container-element~                      |
| ~:html-divs~                                   | ~org-html-divs~                                   |
| ~:html-doctype~                                | ~org-html-doctype~                                |
| ~:html-extension~                              | ~org-html-extension~                              |
| ~:html-footnote-format~                        | ~org-html-footnote-format~                        |
| ~:html-footnote-separator~                     | ~org-html-footnote-separator~                     |
| ~:html-footnotes-section~                      | ~org-html-footnotes-section~                      |
| ~:html-format-drawer-function~                 | ~org-html-format-drawer-function~                 |
| ~:html-format-headline-function~               | ~org-html-format-headline-function~               |
| ~:html-format-inlinetask-function~             | ~org-html-format-inlinetask-function~             |
| ~:html-head-extra~                             | ~org-html-head-extra~                             |
| ~:html-head-include-default-style~             | ~org-html-head-include-default-style~             |
| ~:html-head-include-scripts~                   | ~org-html-head-include-scripts~                   |
| ~:html-head~                                   | ~org-html-head~                                   |
| ~:html-home/up-format~                         | ~org-html-home/up-format~                         |
| ~:html-html5-fancy~                            | ~org-html-html5-fancy~                            |
| ~:html-indent~                                 | ~org-html-indent~                                 |
| ~:html-infojs-options~                         | ~org-html-infojs-options~                         |
| ~:html-infojs-template~                        | ~org-html-infojs-template~                        |
| ~:html-inline-image-rules~                     | ~org-html-inline-image-rules~                     |
| ~:html-inline-images~                          | ~org-html-inline-images~                          |
| ~:html-link-home~                              | ~org-html-link-home~                              |
| ~:html-link-org-files-as-html~                 | ~org-html-link-org-files-as-html~                 |
| ~:html-link-up~                                | ~org-html-link-up~                                |
| ~:html-link-use-abs-url~                       | ~org-html-link-use-abs-url~                       |
| ~:html-mathjax-options~                        | ~org-html-mathjax-options~                        |
| ~:html-mathjax-template~                       | ~org-html-mathjax-template~                       |
| ~:html-equation-reference-format~              | ~org-html-equation-reference-format~              |
| ~:html-metadata-timestamp-format~              | ~org-html-metadata-timestamp-format~              |
| ~:html-postamble-format~                       | ~org-html-postamble-format~                       |
| ~:html-postamble~                              | ~org-html-postamble~                              |
| ~:html-preamble-format~                        | ~org-html-preamble-format~                        |
| ~:html-preamble~                               | ~org-html-preamble~                               |
| ~:html-self-link-headlines~                    | ~org-html-self-link-headlines~                    |
| ~:html-table-align-individual-field~           | ~org-html-table-align-individual-fields~          |
| ~:html-table-attributes~                       | ~org-html-table-default-attributes~               |
| ~:html-table-caption-above~                    | ~org-html-table-caption-above~                    |
| ~:html-table-data-tags~                        | ~org-html-table-data-tags~                        |
| ~:html-table-header-tags~                      | ~org-html-table-header-tags~                      |
| ~:html-table-row-tags~                         | ~org-html-table-row-tags~                         |
| ~:html-table-use-header-tags-for-first-column~ | ~org-html-table-use-header-tags-for-first-column~ |
| ~:html-tag-class-prefix~                       | ~org-html-tag-class-prefix~                       |
| ~:html-text-markup-alist~                      | ~org-html-text-markup-alist~                      |
| ~:html-todo-kwd-class-prefix~                  | ~org-html-todo-kwd-class-prefix~                  |
| ~:html-toplevel-hlevel~                        | ~org-html-toplevel-hlevel~                        |
| ~:html-use-infojs~                             | ~org-html-use-infojs~                             |
| ~:html-validation-link~                        | ~org-html-validation-link~                        |
| ~:html-viewport~                               | ~org-html-viewport~                               |
| ~:html-wrap-src-lines~                         | ~org-html-wrap-src-lines~                         |
| ~:html-xml-declaration~                        | ~org-html-xml-declaration~                        |

**** LaTeX specific properties
:PROPERTIES:
:UNNUMBERED: notoc
:END:

| ~:latex-active-timestamp-format~       | ~org-latex-active-timestamp-format~       |
| ~:latex-caption-above~                 | ~org-latex-caption-above~                 |
| ~:latex-classes~                       | ~org-latex-classes~                       |
| ~:latex-class~                         | ~org-latex-default-class~                 |
| ~:latex-compiler~                      | ~org-latex-compiler~                      |
| ~:latex-default-figure-position~       | ~org-latex-default-figure-position~       |
| ~:latex-default-table-environment~     | ~org-latex-default-table-environment~     |
| ~:latex-default-table-mode~            | ~org-latex-default-table-mode~            |
| ~:latex-diary-timestamp-format~        | ~org-latex-diary-timestamp-format~        |
| ~:latex-engraved-options~              | ~org-latex-engraved-options~              |
| ~:latex-engraved-preamble~             | ~org-latex-engraved-preamble~             |
| ~:latex-engraved-theme~                | ~org-latex-engraved-theme~                |
| ~:latex-footnote-defined-format~       | ~org-latex-footnote-defined-format~       |
| ~:latex-footnote-separator~            | ~org-latex-footnote-separator~            |
| ~:latex-format-drawer-function~        | ~org-latex-format-drawer-function~        |
| ~:latex-format-headline-function~      | ~org-latex-format-headline-function~      |
| ~:latex-format-inlinetask-function~    | ~org-latex-format-inlinetask-function~    |
| ~:latex-hyperref-template~             | ~org-latex-hyperref-template~             |
| ~:latex-image-default-height~          | ~org-latex-image-default-height~          |
| ~:latex-image-default-option~          | ~org-latex-image-default-option~          |
| ~:latex-image-default-width~           | ~org-latex-image-default-width~           |
| ~:latex-images-centered~               | ~org-latex-images-centered~               |
| ~:latex-inactive-timestamp-format~     | ~org-latex-inactive-timestamp-format~     |
| ~:latex-inline-image-rules~            | ~org-latex-inline-image-rules~            |
| ~:latex-link-with-unknown-path-format~ | ~org-latex-link-with-unknown-path-format~ |
| ~:latex-listings-langs~                | ~org-latex-listings-langs~                |
| ~:latex-listings-options~              | ~org-latex-listings-options~              |
| ~:latex-minted-langs~                  | ~org-latex-minted-langs~                  |
| ~:latex-minted-options~                | ~org-latex-minted-options~                |
| ~:latex-prefer-user-labels~            | ~org-latex-prefer-user-labels~            |
| ~:latex-subtitle-format~               | ~org-latex-subtitle-format~               |
| ~:latex-subtitle-separate~             | ~org-latex-subtitle-separate~             |
| ~:latex-src-block-backend~             | ~org-latex-src-block-backend~             |
| ~:latex-table-scientific-notation~     | ~org-latex-table-scientific-notation~     |
| ~:latex-tables-booktabs~               | ~org-latex-tables-booktabs~               |
| ~:latex-tables-centered~               | ~org-latex-tables-centered~               |
| ~:latex-text-markup-alist~             | ~org-latex-text-markup-alist~             |
| ~:latex-title-command~                 | ~org-latex-title-command~                 |
| ~:latex-toc-command~                   | ~org-latex-toc-command~                   |

**** Markdown specific properties
:PROPERTIES:
:UNNUMBERED: notoc
:END:

| ~:md-footnote-format~   | ~org-md-footnote-format~   |
| ~:md-footnotes-section~ | ~org-md-footnotes-section~ |
| ~:md-headline-style~    | ~org-md-headline-style~    |
| ~:md-toplevel-hlevel~   | ~org-md-toplevel-hlevel~   |

**** ODT specific properties
:PROPERTIES:
:UNNUMBERED: notoc
:END:

| ~:odt-content-template-file~      | ~org-odt-content-template-file~      |
| ~:odt-display-outline-level~      | ~org-odt-display-outline-level~      |
| ~:odt-fontify-srcblocks~          | ~org-odt-fontify-srcblocks~          |
| ~:odt-format-drawer-function~     | ~org-odt-format-drawer-function~     |
| ~:odt-format-headline-function~   | ~org-odt-format-headline-function~   |
| ~:odt-format-inlinetask-function~ | ~org-odt-format-inlinetask-function~ |
| ~:odt-inline-formula-rules~       | ~org-odt-inline-formula-rules~       |
| ~:odt-inline-image-rules~         | ~org-odt-inline-image-rules~         |
| ~:odt-pixels-per-inch~            | ~org-odt-pixels-per-inch~            |
| ~:odt-styles-file~                | ~org-odt-styles-file~                |
| ~:odt-table-styles~               | ~org-odt-table-styles~               |
| ~:odt-use-date-fields~            | ~org-odt-use-date-fields~            |

**** Texinfo specific properties
:PROPERTIES:
:UNNUMBERED: notoc
:END:

| ~:texinfo-active-timestamp-format~       | ~org-texinfo-active-timestamp-format~       |
| ~:texinfo-classes~                       | ~org-texinfo-classes~                       |
| ~:texinfo-class~                         | ~org-texinfo-default-class~                 |
| ~:texinfo-compact-itemx                  | ~org-texinfo-compact-itemx~                 |
| ~:texinfo-table-default-markup~          | ~org-texinfo-table-default-markup~          |
| ~:texinfo-diary-timestamp-format~        | ~org-texinfo-diary-timestamp-format~        |
| ~:texinfo-filename~                      | ~org-texinfo-filename~                      |
| ~:texinfo-format-drawer-function~        | ~org-texinfo-format-drawer-function~        |
| ~:texinfo-format-headline-function~      | ~org-texinfo-format-headline-function~      |
| ~:texinfo-format-inlinetask-function~    | ~org-texinfo-format-inlinetask-function~    |
| ~:texinfo-inactive-timestamp-format~     | ~org-texinfo-inactive-timestamp-format~     |
| ~:texinfo-link-with-unknown-path-format~ | ~org-texinfo-link-with-unknown-path-format~ |
| ~:texinfo-node-description-column~       | ~org-texinfo-node-description-column~       |
| ~:texinfo-table-scientific-notation~     | ~org-texinfo-table-scientific-notation~     |
| ~:texinfo-tables-verbatim~               | ~org-texinfo-tables-verbatim~               |
| ~:texinfo-text-markup-alist~             | ~org-texinfo-text-markup-alist~             |

*** Publishing links
:PROPERTIES:
:DESCRIPTION: Which links keep working after publishing?
:END:
#+cindex: links, publishing

To create a link from one Org file to another, you would use something
like =[[file:foo.org][The foo]]= or simply =[[file:foo.org]]= (see
[[*External Links]]).  When published, this link becomes a link to
=foo.html=.  You can thus interlink the pages of your "Org web"
project and the links will work as expected when you publish them to
HTML.  If you also publish the Org source file and want to link to it,
use an =http= link instead of a =file:= link, because =file= links are
converted to link to the corresponding =.html= file.

Links to encrypted Org files, like =[[file:foo.org.gpg]]= are also
supported.

You may also link to related files, such as images.  Provided you are
careful with relative file names, and provided you have also
configured Org to upload the related files, these links will work too.
See [[*Example: complex publishing configuration]], for an example of this
usage.

Links between published documents can contain some search options (see
[[*Search Options in File Links]]), which will be resolved to the
appropriate location in the linked file.  For example, once published
to HTML, the following links all point to a dedicated anchor in
=foo.html=.

#+begin_example
[[file:foo.org::*heading]]
[[file:foo.org::#custom-id]]
[[file:foo.org::target]]
#+end_example

*** Generating a sitemap
:PROPERTIES:
:DESCRIPTION: Generating a list of all pages.
:ALT_TITLE: Site map
:END:
#+cindex: sitemap, of published pages

The following properties may be used to control publishing of
a map of files for a given project.

- ~:auto-sitemap~ ::

  When non-~nil~, publish a sitemap during
  ~org-publish-current-project~ or ~org-publish-all~.

- ~:sitemap-filename~ ::

  Filename for output of sitemap.  Defaults to =sitemap.org=, which
  becomes =sitemap.html=.

- ~:sitemap-title~ ::

  Title of sitemap page.  Defaults to name of file.

- ~:sitemap-format-entry~ ::

  #+findex: org-publish-find-date
  #+findex: org-publish-find-property
  #+findex: org-publish-find-title
  With this option one can tell how a site-map entry is formatted in
  the site-map.  It is a function called with three arguments: the
  file or directory name relative to base directory of the project,
  the site-map style and the current project.  It is expected to
  return a string.  Default value turns file names into links and use
  document titles as descriptions.  For specific formatting needs, one
  can use ~org-publish-find-date~, ~org-publish-find-title~ and
  ~org-publish-find-property~, to retrieve additional information
  about published documents.

- ~:sitemap-function~ ::

  Plug-in function to use for generation of the sitemap.  It is called
  with two arguments: the title of the site-map and a representation
  of the files and directories involved in the project as a nested
  list, which can further be transformed using ~org-list-to-generic~,
  ~org-list-to-subtree~ and alike.  Default value generates a plain
  list of links to all files in the project.

- ~:sitemap-sort-folders~ ::

  Where folders should appear in the sitemap.  Set this to ~first~
  (default) or ~last~ to display folders first or last, respectively.
  When set to ~ignore~, folders are ignored altogether.  Any other
  value mixes files and folders.  This variable has no effect when
  site-map style is ~tree~.

- ~:sitemap-sort-files~ ::

  How the files are sorted in the site map.  Set this to
  ~alphabetically~ (default), ~chronologically~ or
  ~anti-chronologically~.  ~chronologically~ sorts the files with
  older date first while ~anti-chronologically~ sorts the files with
  newer date first.  ~alphabetically~ sorts the files alphabetically.
  The date of a file is retrieved with ~org-publish-find-date~.

- ~:sitemap-ignore-case~ ::

  Should sorting be case-sensitive?  Default ~nil~.

- ~:sitemap-file-entry-format~ ::

  With this option one can tell how a sitemap's entry is formatted in
  the sitemap.  This is a format string with some escape sequences:
  ~%t~ stands for the title of the file, ~%a~ stands for the author of
  the file and ~%d~ stands for the date of the file.  The date is
  retrieved with the ~org-publish-find-date~ function and formatted
  with ~org-publish-sitemap-date-format~.  Default ~%t~.

- ~:sitemap-date-format~ ::

  Format string for the ~format-time-string~ function that tells how
  a sitemap entry's date is to be formatted.  This property bypasses
  ~org-publish-sitemap-date-format~ which defaults to ~%Y-%m-%d~.

*** Generating an index
:PROPERTIES:
:DESCRIPTION: An index that reaches across pages.
:END:
#+cindex: index, in a publishing project

Org mode can generate an index across the files of a publishing project.

- ~:makeindex~ ::

  When non-~nil~, generate in index in the file =theindex.org= and
  publish it as =theindex.html=.

The file is created when first publishing a project with the
~:makeindex~ set.  The file only contains a statement =#+INCLUDE:
"theindex.inc"=.  You can then build around this include statement by
adding a title, style information, etc.

#+cindex: @samp{INDEX}, keyword
Index entries are specified with =INDEX= keyword.  An entry that
contains an exclamation mark creates a sub item.

#+begin_example
,*** Curriculum Vitae
,#+INDEX: CV
,#+INDEX: Application!CV
#+end_example

** Uploading Files
:PROPERTIES:
:DESCRIPTION: How to get files up on the server.
:END:
#+cindex: rsync
#+cindex: unison

For those people already utilizing third party sync tools such as
Rsync or Unison, it might be preferable not to use the built-in remote
publishing facilities of Org mode which rely heavily on Tramp.  Tramp,
while very useful and powerful, tends not to be so efficient for
multiple file transfer and has been known to cause problems under
heavy usage.

Specialized synchronization utilities offer several advantages.  In
addition to timestamp comparison, they also do content and
permissions/attribute checks.  For this reason you might prefer to
publish your web to a local directory---possibly even /in place/ with
your Org files---and then use Unison or Rsync to do the
synchronization with the remote host.

Since Unison, for example, can be configured as to which files to
transfer to a certain remote destination, it can greatly simplify the
project publishing definition.  Simply keep all files in the correct
location, process your Org files with ~org-publish~ and let the
synchronization tool do the rest.  You do not need, in this scenario,
to include attachments such as JPG, CSS or PNG files in the project
definition since the third-party tool syncs them.

Publishing to a local directory is also much faster than to a remote
one, so that you can afford more easily to republish entire projects.
If you set ~org-publish-use-timestamps-flag~ to ~nil~, you gain the
main benefit of re-including any changed external files such as source
example files you might include with =INCLUDE= keyword.  The timestamp
mechanism in Org is not smart enough to detect if included files have
been modified.

** Sample Configuration
:PROPERTIES:
:DESCRIPTION: Example projects.
:END:

Below we provide two example configurations.  The first one is
a simple project publishing only a set of Org files.  The second
example is more complex, with a multi-component project.

*** Example: simple publishing configuration
:PROPERTIES:
:DESCRIPTION: One-component publishing.
:ALT_TITLE: Simple example
:END:

This example publishes a set of Org files to the =public_html=
directory on the local machine.

#+begin_src emacs-lisp
(setq org-publish-project-alist
      '(("org"
         :base-directory "~/org/"
         :publishing-function org-html-publish-to-html
         :publishing-directory "~/public_html"
         :section-numbers nil
         :with-toc nil
         :html-head "<link rel=\"stylesheet\"
                    href=\"../other/mystyle.css\"
                    type=\"text/css\"/>")))
#+end_src

*** Example: complex publishing configuration
:PROPERTIES:
:DESCRIPTION: A multi-component publishing example.
:ALT_TITLE: Complex example
:END:

This more complicated example publishes an entire website, including
Org files converted to HTML, image files, Emacs Lisp source code, and
style sheets.  The publishing directory is remote and private files
are excluded.

To ensure that links are preserved, care should be taken to replicate
your directory structure on the web server, and to use relative file
paths.  For example, if your Org files are kept in =~/org/= and your
publishable images in =~/images/=, you would link to an image with

: file:../images/myimage.png

On the web server, the relative path to the image should be the same.
You can accomplish this by setting up an =images/= folder in the right
place on the web server, and publishing images to it.

#+begin_src emacs-lisp
(setq org-publish-project-alist
      '(("orgfiles"
         :base-directory "~/org/"
         :base-extension "org"
         :publishing-directory "/ssh:user@host:~/html/notebook/"
         :publishing-function org-html-publish-to-html
         :exclude "PrivatePage.org" ;; regexp
         :headline-levels 3
         :section-numbers nil
         :with-toc nil
         :html-head "<link rel=\"stylesheet\"
                  href=\"../other/mystyle.css\" type=\"text/css\"/>"
         :html-preamble t)

        ("images"
         :base-directory "~/images/"
         :base-extension "jpg\\|gif\\|png"
         :publishing-directory "/ssh:user@host:~/html/images/"
         :publishing-function org-publish-attachment)

        ("other"
         :base-directory "~/other/"
         :base-extension "css\\|el"
         :publishing-directory "/ssh:user@host:~/html/other/"
         :publishing-function org-publish-attachment)
        ("website" :components ("orgfiles" "images" "other"))))
#+end_src

** Triggering Publication
:PROPERTIES:
:DESCRIPTION: Publication commands.
:END:

Once properly configured, Org can publish with the following commands:

- {{{kbd(C-c C-e P x)}}} (~org-publish~) ::

  #+kindex: C-c C-e P x
  #+findex: org-publish
  Prompt for a specific project and publish all files that belong to
  it.

- {{{kbd(C-c C-e P p)}}} (~org-publish-current-project~) ::

  #+kindex: C-c C-e P p
  #+findex: org-publish-current-project
  Publish the project containing the current file.

- {{{kbd(C-c C-e P f)}}} (~org-publish-current-file~) ::

  #+kindex: C-c C-e P f
  #+findex: org-publish-current-file
  Publish only the current file.

- {{{kbd(C-c C-e P a)}}} (~org-publish-all~) ::

  #+kindex: C-c C-e P a
  #+findex: org-publish-all
  Publish every project.

#+vindex: org-publish-use-timestamps-flag
Org uses timestamps to track when a file has changed.  The above
functions normally only publish changed files.  You can override this
and force publishing of all files by giving a prefix argument to any
of the commands above, or by customizing the variable
~org-publish-use-timestamps-flag~.  This may be necessary in
particular if files include other files via =SETUPFILE= or =INCLUDE=
keywords.

* Citation handling
:PROPERTIES:
:DESCRIPTION: create, follow and export citations.
:END:
#+cindex: citation

The =oc.el= library provides tooling to handle citations in Org via
"citation processors" that offer some or all of the following
capabilities:

- activate :: Fontification, tooltip preview, etc.
- follow :: At-point actions on citations via ~org-open-at-point~.
- insert :: Add and edit citations via ~org-cite-insert~.
- export :: Via different libraries for different target formats.

To use a "citation processor", the user must load them; for example;

#+begin_src emacs-lisp
(require 'oc-bibtex)
#+end_src

They can then configure them with ~org-cite-activate-processor~,
~org-cite-follow-processor~, ~org-cite-insert-processor~, and
~org-cite-export-processors~ respectively.

The included "basic" processor provides all four capabilities.

** Citations

Before adding citations, first set one-or-more bibliographies, either
globally with ~org-cite-global-bibliography~, or locally using one or
more "bibliography" keywords.

#+begin_example
#+bibliography: SomeFile.bib
#+bibliography: /some/other/file.json
#+bibliography: "/some/file/with spaces/in its name.bib"
#+end_example

#+kindex: C-c C-x @@
#+findex: org-cite-insert
One can then insert and edit citations using ~org-cite-insert~, called
with {{{kbd(C-c C-x @)}}}.

A /citation/ requires one or more citation /key(s)/, elements
identifying a reference in the bibliography.

- Each citation is surrounded by brackets and uses the =cite= type.

- Each key starts with the character =@=.

- Each key can be qualified by a /prefix/ (e.g.\nbsp{}"see ") and/or
  a /suffix/ (e.g.\nbsp{}"p.\nbsp{}123"), giving information useful or necessary
  for the comprehension of the citation but not included in the
  reference.

- A single citation can cite more than one reference ; the keys are
  separated by semicolons ; the formatting of such citation groups is
  specified by the style.

- One can also specify a stylistic variation for the citations by
  inserting a =/= and a style name between the =cite= keyword and the
  colon; this usually makes sense only for the author-year styles.

: [cite/style:common prefix ;prefix @key suffix; ... ; common suffix]

The only mandatory elements are:

- The =cite= keyword and the colon.
- The =@= character immediately preceding each key.
- The brackets surrounding the citation(s) (group).

** Citation export processors

Org currently includes the following export processors:

- Two processors can export to a variety of formats, including =latex=
  (and therefore =pdf=), =html=, =odt= and plain (UTF8) text:

  - basic :: a basic export processor, well adapted to situations
    where backward compatibility is not a requirement and formatting
    needs are minimal;

  - csl :: this export processor uses format files written in [[https://en.wikipedia.org/wiki/Citation_Style_Language][Citation
    Style Language]] via [[https://github.com/andras-simonyi/citeproc-el][citeproc-el]];

- In contrast, three other processors target LaTeX and LaTeX-derived
  formats exclusively:

  - bibtex :: this export processor uses BibTeX, the historical
    bibliographic processor used with LaTeX, thus allowing the use of
    data and style files compatible with this processor (including a
    large number of publishers' styles). It only supports LaTeX's
    =\cite= and =\nocite= commands.

  - natbib :: as with the bibtex processor, but using the LaTeX
    package =natbib=, allowing more stylistic variants that LaTeX's
    =\cite= command.

  - biblatex :: this backend allows the use of data and formats
    prepared for BibLaTeX, an alternate bibliographic processor used
    with LaTeX, which overcomes some serious BibTeX limitations, but
    has not (yet?)\nbsp{}been widely adopted by publishers.

The =CITE_EXPORT= keyword specifies the export processor and the
citation (and possibly reference) style(s); for example (all arguments
are optional)

: #+cite_export: basic author author-year

#+texinfo: @noindent
specifies the "basic" export processor with citations inserted as
author's name and references indexed by author's names and year;

: #+cite_export: csl /some/path/to/vancouver-brackets.csl

#+texinfo: @noindent
specifies the "csl" processor and CSL style, which in this case
defines numeric citations and numeric references according to the
=Vancouver= specification (as style used in many medical journals),
following a typesetting variation putting citations between brackets;

: #+cite_export: natbib kluwer

#+texinfo: @noindent
specifies the =natbib= export processor with a label citation style
conformant to the Harvard style and the specification of the
Wolkers-Kluwer publisher; since it relies on the ~bibtex~ processor of
your LaTeX installation, it won't export to anything but PDF.

** Bibliography printing

The =PRINT_BIBLIOGRAPHY= keyword specifies where the bibliography
should be printed (note the colon):

: #+print_bibliography:

The bibliography printed by the LaTeX-based export processors
"bibtex", "natbib" and "biblatex" has a chapter or section heading by
default, while the "basic" and "csl" processors print the list of
bibliography entries without a heading.

A document may contain more than one =PRINT_BIBLIOGRAPHY= keywords.
Each of the keywords will trigger printing the bibliography.

The keywords can be used with or without additional options.  Options
can be used, for example, to print only entries that belong to a
certain category or to control formatting.  The set of supported
=PRINT_BIBLIOGRAPHY= options and their interpretation varies between
the different citation export processors.  Some export processors do
not support passing options.

*** Bibliography options in the "biblatex" and "csl" export processors

The "biblatex" and "csl" export processors support bibliography
options through a property list attached to the =PRINT_BIBLIOGRAPHY=
keyword.  For example,

: #print_bibliography: :keyword algebra :type book

Values including spaces must be surrounded with double quotes.  If you
need to use a key multiple times, you can separate its values with
commas, but without any space in-between:

: #print_bibliography: :keyword "algebraic logic" :nottype article,book

The "biblatex" export processor accepts all options supported by
BibLaTeX's ~\printbibliography~ command, while the "csl" processor
accepts the following ones:

- =:keyword <keyword(,keyword2...)>= :: Print only entries whose
  keyword field contains all given keywords.

- =:notkeyword <keyword(,keyword2...)>= :: Print only entries whose
  keyword field does not contain any of the given keywords.

- =:type <entrytype>= :: Print only entries whose type is
  =<entrytype>=.  Entry type is the BibTeX/BibLaTeX entry type if this
  information is available (the entry was read from a BibTeX/BibLaTeX
  bibliography) and the CSL entry type otherwise.

- =:nottype <entrytype(,entrytype2...)>= :: Print only entries whose
  type is not among the given entry types.  Entry type is determined
  as in the case of =:type=.

- =:csltype <entrytype>= :: Print only entries whose CSL entry type
  (possibly based on a conversion from BibTeX/BibLaTeX to CSL) is
  =<entrytype>=.

- =:notcsltype <entrytype(,entrytype2...)>= :: Print only entries whose
  CSL entry type (possibly based on a conversion from BibTeX/BibLaTeX
  to CSL) is not among the listed entry types.

- =:filter <predicate>= :: Print only entries for which the given
  Emacs Lisp predicate returns a non-~nil~ value.

* Working with Source Code
:PROPERTIES:
:DESCRIPTION: Export, evaluate, and tangle code blocks.
:END:
#+cindex: source code, working with

Source code here refers to any plain text collection of computer
instructions, possibly with comments, written using a human-readable
programming language.  Org can manage source code in an Org document
when the source code is identified with begin and end markers.
Working with source code begins with identifying source code blocks.
A source code block can be placed almost anywhere in an Org document;
it is not restricted to the preamble or the end of the document.
However, Org cannot manage a source code block if it is placed inside
an Org comment or within a fixed width section.

Here is an example source code block in the Emacs Lisp language:

#+begin_example
,#+BEGIN_SRC emacs-lisp
  (defun org-xor (a b)
     "Exclusive or."
     (if a (not b) b))
,#+END_SRC
#+end_example

Source code blocks are one of many Org block types, which also include
"center", "comment", "dynamic", "example", "export", "quote",
"special", and "verse".  This section pertains to blocks between
=#+BEGIN_SRC= and =#+END_SRC=.

Details of Org's facilities for working with source code are described
in the following sections.

** Features Overview
:PROPERTIES:
:DESCRIPTION: Enjoy the versatility of source blocks.
:END:

Org can manage the source code in the block delimited by =#+BEGIN_SRC=
... =#+END_SRC= in several ways that can simplify housekeeping tasks
essential to modern source code maintenance.  Org can edit, format,
extract, export, and publish source code blocks.  Org can also compile
and execute a source code block, then capture the results.  The Org
mode literature sometimes refers to source code blocks as /live code/
blocks because they can alter the content of the Org document or the
material that it exports.  Users can control the "liveliness" of each
source code block by tweaking the header arguments (see [[*Using Header
Arguments]]) for compiling, execution, extraction, and exporting.

For editing and formatting a source code block, Org uses an
appropriate Emacs major mode that includes features specifically
designed for source code in that language.

Org can extract one or more source code blocks and write them to one
or more source files---a process known as /tangling/ in literate
programming terminology.

For exporting and publishing, Org's back-ends can format a source code
block appropriately, often with native syntax highlighting.

For executing and compiling a source code block, the user can
configure Org to select the appropriate compiler.  Org provides
facilities to collect the result of the execution or compiler output,
insert it into the Org document, and/or export it.  In addition to
text results, Org can insert links to other data types, including
audio, video, and graphics.  Org can also link a compiler error
message to the appropriate line in the source code block.

An important feature of Org's management of source code blocks is the
ability to pass variables, functions, and results to one another using
a common syntax for source code blocks in any language.  Although most
literate programming facilities are restricted to one language or
another, Org's language-agnostic approach lets the literate programmer
match each programming task with the appropriate computer language and
to mix them all together in a single Org document.  This
interoperability among languages explains why Org's source code
management facility was named /Org Babel/ by its originators, Eric
Schulte and Dan Davison.

Org mode fulfills the promise of easy verification and maintenance of
publishing reproducible research by keeping text, data, code,
configuration settings of the execution environment, the results of
the execution, and associated narratives, claims, references, and
internal and external links in a single Org document.

** Structure of Code Blocks
:PROPERTIES:
:DESCRIPTION: Code block syntax described.
:END:
#+cindex: code block, structure
#+cindex: source code, block structure
#+cindex: @samp{NAME} keyword, in source blocks
#+cindex: @samp{BEGIN_SRC}

Org offers two ways to structure source code in Org documents: in
a source code block, and directly inline.  Both specifications are
shown below.

A source code block conforms to this structure:

#+begin_example
,#+NAME: <name>
,#+BEGIN_SRC <language> <switches> <header arguments>
  <body>
,#+END_SRC
#+end_example

Do not be put-off by having to remember the source block syntax.  Org
mode offers a command for wrapping existing text in a block (see
[[*Structure Templates]]).  Org also works with other completion systems
in Emacs, some of which predate Org and have custom domain-specific
languages for defining templates.  Regular use of templates reduces
errors, increases accuracy, and maintains consistency.

#+cindex: source code, inline
An inline code block conforms to this structure:

: src_<language>{<body>}

#+texinfo: @noindent
or

: src_<language>[<header arguments>]{<body>}

- =#+NAME: <name>= ::

  Optional.  Names the source block so it can be called, like
  a function, from other source blocks or inline code to evaluate or
  to capture the results.  Code from other blocks, other files, and
  from table formulas (see [[*The Spreadsheet]]) can use the name to
  reference a source block.  This naming serves the same purpose as
  naming Org tables.  Org mode requires unique names.  For duplicate
  names, Org mode's behavior is undefined.

- =#+BEGIN_SRC= ... =#+END_SRC= ::

  Mandatory.  They mark the start and end of a block that Org
  requires.  The =#+BEGIN_SRC= line takes additional arguments, as
  described next.

- =<language>= ::

  #+cindex: language, in code blocks
  Mandatory.  It is the identifier of the source code language in the
  block.  See [[*Languages]], for identifiers of supported languages.

- =<switches>= ::

  #+cindex: switches, in code blocks
  Optional.  Switches provide finer control of the code execution,
  export, and format (see the discussion of switches in [[*Literal
  Examples]]).

- =<header arguments>= ::

  #+cindex: header arguments, in code blocks
  Optional.  Heading arguments control many aspects of evaluation,
  export and tangling of code blocks (see [[*Using Header Arguments]]).
  Using Org's properties feature, header arguments can be selectively
  applied to the entire buffer or specific subtrees of the Org
  document.

- =<body>= ::

  Source code in the dialect of the specified language identifier.

** Using Header Arguments
:PROPERTIES:
:DESCRIPTION: Different ways to set header arguments.
:END:

Org comes with many header arguments common to all languages.  New
header arguments are added for specific languages as they become
available for use in source code blocks.  A header argument is
specified with an initial colon followed by the argument's name in
lowercase.

Since header arguments can be set in several ways, Org prioritizes
them in case of overlaps or conflicts by giving local settings
a higher priority.  Header values in function calls, for example,
override header values from global defaults.

*** System-wide header arguments
:PROPERTIES:
:UNNUMBERED: notoc
:END:
#+vindex: org-babel-default-header-args

#+vindex: org-babel-default-header-args
System-wide values of header arguments can be specified by customizing
the ~org-babel-default-header-args~ variable, which defaults to the
following values:

#+begin_example
:session    => "none"
:results    => "replace"
:exports    => "code"
:cache      => "no"
:noweb      => "no"
:hlines     => "no"
:tangle     => "no"
#+end_example

#+vindex: org-babel-default-inline-header-args
Inline source blocks (see [[*Structure of Code Blocks]]) use slightly
different default header arguments defined in
~org-babel-default-inline-header-args~:

#+begin_example
:session    => "none"
:results    => "replace"
:exports    => "results"
:hlines     => "yes"
#+end_example

The most notable difference between default header arguments for
inline and normal source blocks is =:exports= argument.  For inline
source blocks, results of evaluation are exported by default; not the
code.

Unlike the default values, header arguments set using Org mode
properties (see [[*Header arguments in Org mode properties]]) do apply to
both the normal source blocks and inline source blocks.

The example below sets =:noweb= header arguments to =yes=, which makes
Org expand =:noweb= references by default.

#+begin_src emacs-lisp
(setq org-babel-default-header-args
      (cons '(:noweb . "yes")
            (assq-delete-all :noweb org-babel-default-header-args)))
#+end_src

#+cindex: language specific default header arguments
#+cindex: default header arguments per language
Each language can have separate default header arguments by
customizing the variable ~org-babel-default-header-args:<LANG>~, where
{{{var(<LANG>)}}} is the name of the language.  For details, see the
language-specific online documentation at
https://orgmode.org/worg/org-contrib/babel/.

*** Header arguments in Org mode properties
:PROPERTIES:
:UNNUMBERED: notoc
:END:

For header arguments applicable to the buffer, use =PROPERTY= keyword
anywhere in the Org file (see [[*Property Syntax]]).

The following example makes all the R code blocks execute in the same
session.  Setting =:results= to =silent= ignores the results of
executions for all blocks, not just R code blocks; no results inserted
for any block.

#+begin_example
,#+PROPERTY: header-args:R  :session *R*
,#+PROPERTY: header-args    :results silent
#+end_example

#+vindex: org-use-property-inheritance
Header arguments set through Org's property drawers (see [[*Property
Syntax]]) apply at the subtree level on down.  Since these property
drawers can appear anywhere in the file hierarchy, Org uses outermost
call or source block to resolve the values.  Org ignores
~org-use-property-inheritance~ setting.

In this example, =:cache= defaults to =yes= for all code blocks in the
subtree.

#+begin_example
,* sample header
  :PROPERTIES:
  :header-args:    :cache yes
  :END:
#+end_example

#+kindex: C-c C-x p
#+findex: org-set-property
Properties defined through ~org-set-property~ function, bound to
{{{kbd(C-c C-x p)}}}, apply to all active languages.  They override
properties set in ~org-babel-default-header-args~.

#+cindex: language specific header arguments properties
#+cindex: header arguments per language
Language-specific header arguments are also read from properties
=header-args:<LANG>= where {{{var(<LANG>)}}} is the language
identifier.  For example,

#+begin_example
,* Heading
  :PROPERTIES:
  :header-args:clojure:    :session *clojure-1*
  :header-args:R:          :session *R*
  :END:
,** Subheading
  :PROPERTIES:
  :header-args:clojure:    :session *clojure-2*
  :END:
#+end_example

#+texinfo: @noindent
would force separate sessions for Clojure blocks in =Heading= and
=Subheading=, but use the same session for all R blocks.  Blocks in
=Subheading= inherit settings from =Heading=.

*** Code block specific header arguments
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Header arguments are most commonly set at the source code block level,
on the =#+BEGIN_SRC= line.  Arguments set at this level take
precedence over those set in the ~org-babel-default-header-args~
variable, and also those set as header properties.

In the following example, setting =:results= to =silent= makes it
ignore results of the code execution.  Setting =:exports= to =code=
exports only the body of the code block to HTML or LaTeX.

#+begin_example
,#+NAME: factorial
,#+BEGIN_SRC haskell :results silent :exports code :var n=0
  fac 0 = 1
  fac n = n * fac (n-1)
,#+END_SRC
#+end_example

The same header arguments in an inline code block:

: src_haskell[:exports both]{fac 5}

#+cindex: @samp{HEADER}, keyword
Code block header arguments can span multiple lines using =#+HEADER:=
on each line.  Note that Org currently accepts the plural spelling of
=#+HEADER:= only as a convenience for backward-compatibility.  It may
be removed at some point.

Multi-line header arguments on an unnamed code block:

#+begin_example
,#+HEADER: :var data1=1
,#+BEGIN_SRC emacs-lisp :var data2=2
   (message "data1:%S, data2:%S" data1 data2)
,#+END_SRC

,#+RESULTS:
: data1:1, data2:2
#+end_example

Multi-line header arguments on a named code block:

#+begin_example
,#+NAME: named-block
,#+HEADER: :var data=2
,#+BEGIN_SRC emacs-lisp
  (message "data:%S" data)
,#+END_SRC

,#+RESULTS: named-block
  : data:2
#+end_example

*** Header arguments in function calls
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Header arguments in function calls are the most specific and override
all other settings in case of an overlap.  They get the highest
priority.  Two =#+CALL:= examples are shown below.  For the complete
syntax of =CALL= keyword, see [[*Evaluating Code Blocks]].

In this example, =:exports results= header argument is applied to the
evaluation of the =#+CALL:= line.

: #+CALL: factorial(n=5) :exports results

In this example, =:session special= header argument is applied to the
evaluation of =factorial= code block.

: #+CALL: factorial[:session special](n=5)

** Environment of a Code Block
:PROPERTIES:
:DESCRIPTION: Arguments, sessions, working directory...
:END:

*** Passing arguments
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: passing arguments to code blocks
#+cindex: arguments, in code blocks
#+cindex: @samp{var}, header argument
Use =var= for passing arguments to source code blocks.  The specifics
of variables in code blocks vary by the source language and are
covered in the language-specific documentation.  The syntax for =var=,
however, is the same for all languages.  This includes declaring
a variable, and assigning a default value.

The following syntax is used to pass arguments to code blocks using
the =var= header argument.

: :var NAME=ASSIGN

#+texinfo: @noindent
{{{var(NAME)}}} is the name of the variable bound in the code block
body.  {{{var(ASSIGN)}}} is a literal value, such as a string,
a number, a reference to a table, a list, a literal example, another
code block---with or without arguments---or the results of evaluating
a code block.  {{{var(ASSIGN)}}} may specify a filename for references
to elements in a different file, using a =:= to separate the filename
from the reference.

: :var NAME=FILE:REFERENCE

Here are examples of passing values by reference:

- table ::

  A table named with a =NAME= keyword.

  #+begin_example
  ,#+NAME: example-table
  | 1 |
  | 2 |
  | 3 |
  | 4 |

  ,#+NAME: table-length
  ,#+BEGIN_SRC emacs-lisp :var table=example-table
    (length table)
  ,#+END_SRC

  ,#+RESULTS: table-length
  : 4
  #+end_example

  When passing a table, you can treat specially the row, or the
  column, containing labels for the columns, or the rows, in the
  table.

  #+cindex: @samp{colnames}, header argument
  The =colnames= header argument accepts =yes=, =no=, or =nil= values.
  The default value is =nil=: if an input table has column
  names---because the second row is a horizontal rule---then Org
  removes the column names, processes the table, puts back the column
  names, and then writes the table to the results block.  Using =yes=,
  Org does the same to the first row, even if the initial table does
  not contain any horizontal rule.  When set to =no=, Org does not
  pre-process column names at all.

  #+begin_example
  ,#+NAME: less-cols
  | a |
  |---|
  | b |
  | c |

  ,#+BEGIN_SRC python :var tab=less-cols :colnames nil
    return [[val + '*' for val in row] for row in tab]
  ,#+END_SRC

  ,#+RESULTS:
  | a  |
  |----|
  | b* |
  | c* |
  #+end_example

  #+cindex: @samp{rownames}, header argument
  Similarly, the =rownames= header argument can take two values: =yes=
  or =no=.  When set to =yes=, Org removes the first column, processes
  the table, puts back the first column, and then writes the table to
  the results block.  The default is =no=, which means Org does not
  pre-process the first column.  Note that Emacs Lisp code blocks
  ignore =rownames= header argument because of the ease of
  table-handling in Emacs.

  #+begin_example
  ,#+NAME: with-rownames
  | one | 1 | 2 | 3 | 4 |  5 |
  | two | 6 | 7 | 8 | 9 | 10 |

  ,#+BEGIN_SRC python :var tab=with-rownames :rownames yes
    return [[val + 10 for val in row] for row in tab]
  ,#+END_SRC

  ,#+RESULTS:
  | one | 11 | 12 | 13 | 14 | 15 |
  | two | 16 | 17 | 18 | 19 | 20 |
  #+end_example

To refer to a table in another file, join the filename and table name with
a colon, for example: =:var table=other-file.org:example-table=.

- list ::

  A simple named list.

  #+begin_example
  ,#+NAME: example-list
  - simple
    - not
    - nested
  - list

  ,#+BEGIN_SRC emacs-lisp :var x=example-list
    (print x)
  ,#+END_SRC

  ,#+RESULTS:
  | simple | list |
  #+end_example

  Note that only the top level list items are passed along.  Nested
  list items are ignored.

- code block without arguments ::

  A code block name, as assigned by =NAME= keyword from the example
  above, optionally followed by parentheses.

  #+begin_example
  ,#+BEGIN_SRC emacs-lisp :var length=table-length()
    (* 2 length)
  ,#+END_SRC

  ,#+RESULTS:
  : 8
  #+end_example

- code block with arguments ::

  A code block name, as assigned by =NAME= keyword, followed by
  parentheses and optional arguments passed within the parentheses.

  #+begin_example
  ,#+NAME: double
  ,#+BEGIN_SRC emacs-lisp :var input=8
    (* 2 input)
  ,#+END_SRC

  ,#+RESULTS: double
  : 16

  ,#+NAME: squared
  ,#+BEGIN_SRC emacs-lisp :var input=double(input=1)
    (* input input)
  ,#+END_SRC

  ,#+RESULTS: squared
  : 4
  #+end_example

- literal example, or code block contents ::

  A code block or literal example block named with a =NAME= keyword,
  followed by brackets (optional for example blocks).

  #+begin_example
  ,#+NAME: literal-example
  ,#+BEGIN_EXAMPLE
    A literal example
    on two lines
  ,#+END_EXAMPLE

  ,#+NAME: read-literal-example
  ,#+BEGIN_SRC emacs-lisp :var x=literal-example[]
    (concatenate #'string x " for you.")
  ,#+END_SRC

  ,#+RESULTS: read-literal-example
  : A literal example
  : on two lines for you.
  #+end_example

Indexing variable values enables referencing portions of a variable.
Indexes are 0 based with negative values counting backwards from the
end.  If an index is separated by commas then each subsequent section
indexes as the next dimension.  Note that this indexing occurs
/before/ other table-related header arguments are applied, such as
=hlines=, =colnames= and =rownames=.  The following example assigns
the last cell of the first row the table =example-table= to the
variable =data=:

#+begin_example
,#+NAME: example-table
| 1 | a |
| 2 | b |
| 3 | c |
| 4 | d |

,#+BEGIN_SRC emacs-lisp :var data=example-table[0,-1]
  data
,#+END_SRC

,#+RESULTS:
: a
#+end_example

Two integers separated by a colon reference a range of variable
values.  In that case the entire inclusive range is referenced.  For
example the following assigns the middle three rows of =example-table=
to =data=.

#+begin_example
,#+NAME: example-table
| 1 | a |
| 2 | b |
| 3 | c |
| 4 | d |
| 5 | 3 |

,#+BEGIN_SRC emacs-lisp :var data=example-table[1:3]
  data
,#+END_SRC

,#+RESULTS:
| 2 | b |
| 3 | c |
| 4 | d |
#+end_example

To pick the entire range, use an empty index, or the single character
=*=.  =0:-1= does the same thing.  Example below shows how to
reference the first column only.

#+begin_example
,#+NAME: example-table
| 1 | a |
| 2 | b |
| 3 | c |
| 4 | d |

,#+BEGIN_SRC emacs-lisp :var data=example-table[,0]
  data
,#+END_SRC

,#+RESULTS:
| 1 | 2 | 3 | 4 |
#+end_example

Index referencing can be used for tables and code blocks.  Index
referencing can handle any number of dimensions.  Commas delimit
multiple dimensions, as shown below.

#+begin_example
,#+NAME: 3D
,#+BEGIN_SRC emacs-lisp
  '(((1  2  3)  (4  5  6)  (7  8  9))
    ((10 11 12) (13 14 15) (16 17 18))
    ((19 20 21) (22 23 24) (25 26 27)))
,#+END_SRC

,#+BEGIN_SRC emacs-lisp :var data=3D[1,,1]
  data
,#+END_SRC

,#+RESULTS:
| 11 | 14 | 17 |
#+end_example

Note that row names and column names are not removed prior to variable
indexing.  You need to take them into account, even when =colnames= or
=rownames= header arguments remove them.

Emacs lisp code can also set the values for variables.  To
differentiate a value from Lisp code, Org interprets any value
starting with =(=, =[=, ='= or =`= as Emacs Lisp code.  The result of
evaluating that code is then assigned to the value of that variable.
The following example shows how to reliably query and pass the file
name of the Org mode buffer to a code block using headers.  We need
reliability here because the file's name could change once the code in
the block starts executing.

#+begin_example
,#+BEGIN_SRC sh :var filename=(buffer-file-name) :exports both
  wc -w $filename
,#+END_SRC
#+end_example

Note that values read from tables and lists are not mistakenly
evaluated as Emacs Lisp code, as illustrated in the following example.

#+begin_example
,#+NAME: table
| (a b c) |

,#+HEADER: :var data=table[0,0]
,#+BEGIN_SRC perl
  $data
,#+END_SRC

,#+RESULTS:
: (a b c)
#+end_example

*** Using sessions
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: using sessions in code blocks
#+cindex: @samp{session}, header argument
Two code blocks can share the same environment.  The =session= header
argument is for running multiple source code blocks under one session.
Org runs code blocks with the same session name in the same
interpreter process.

- =none= ::

  Default.  Each code block gets a new interpreter process to execute.
  The process terminates once the block is evaluated.

- {{{var(STRING)}}} ::

  Any string besides =none= turns that string into the name of that
  session.  For example, =:session STRING= names it =STRING=.  If
  =session= has no value, then the session name is derived from the
  source language identifier.  Subsequent blocks with the same source
  code language use the same session.  Depending on the language,
  state variables, code from other blocks, and the overall interpreted
  environment may be shared.  Some interpreted languages support
  concurrent sessions when subsequent source code language blocks
  change session names.

Only languages that provide interactive evaluation can have session
support.  Not all languages provide this support, such as C and ditaa.
Even languages, such as Python and Haskell, that do support
interactive evaluation impose limitations on allowable language
constructs that can run interactively.  Org inherits those limitations
for those code blocks running in a session.

*** Choosing a working directory
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: working directory, in a code block
#+cindex: @samp{dir}, header argument
#+cindex: @samp{mkdirp}, header argument
The =dir= header argument specifies the default directory during code
block execution.  If it is absent, then the directory associated with
the current buffer is used.  In other words, supplying =:dir
DIRECTORY= temporarily has the same effect as changing the current
directory with {{{kbd(M-x cd RET DIRECTORY)}}}, and then not setting
=dir=.  Under the surface, =dir= simply sets the value of the Emacs
variable ~default-directory~.  Setting =mkdirp= header argument to
a non-~nil~ value creates the directory, if necessary.

Setting =dir= to the symbol ~attach~ or the string ~"'attach"~ will
set =dir= to the directory returned by ~(org-attach-dir)~, set =:mkdir
yes=, and insert any file paths, as when using =:results file=, which
are under the node's attachment directory using =attachment:= links
instead of the usual =file:= links.  Any returned path outside of the
attachment directory will use =file:= links as per usual.

For example, to save the plot file in the =Work/= folder of the home
directory---notice tilde is expanded:

#+begin_example
,#+BEGIN_SRC R :file myplot.png :dir ~/Work
  matplot(matrix(rnorm(100), 10), type="l")
,#+END_SRC
#+end_example

To evaluate the code block on a remote machine, supply a remote
directory name using Tramp syntax.  For example:

#+begin_example
,#+BEGIN_SRC R :file plot.png :dir /scp:dand@yakuba.princeton.edu:
  plot(1:10, main=system("hostname", intern=TRUE))
,#+END_SRC
#+end_example

Org first captures the text results as usual for insertion in the Org
file.  Then Org also inserts a link to the remote file, thanks to
Emacs Tramp.  Org constructs the remote path to the file name from
=dir= and ~default-directory~, as illustrated here:

: [[file:/scp:dand@yakuba.princeton.edu:/home/dand/plot.png][plot.png]]

When =dir= is used with =session=, Org sets the starting directory for
a new session.  But Org does not alter the directory of an already
existing session.

Do not use =dir= with =:exports results= or with =:exports both= to
avoid Org inserting incorrect links to remote files.  That is because
Org does not expand ~default directory~ to avoid some underlying
portability issues.

*** Inserting headers and footers
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: headers, in code blocks
#+cindex: footers, in code blocks
#+cindex: @samp{prologue}, header argument
The =prologue= header argument is for appending to the top of the code
block for execution, like a reset instruction.  For example, you may
use =:prologue "reset"= in a Gnuplot code block or, for every such
block:

#+begin_src emacs-lisp
(add-to-list 'org-babel-default-header-args:gnuplot
             '((:prologue . "reset")))

#+end_src

#+cindex: @samp{epilogue}, header argument
Likewise, the value of the =epilogue= header argument is for appending
to the end of the code block for execution.

** Evaluating Code Blocks
:PROPERTIES:
:DESCRIPTION: Place results of evaluation in the Org buffer.
:END:
#+cindex: code block, evaluating
#+cindex: source code, evaluating
#+cindex: @samp{RESULTS}, keyword

A note about security: With code evaluation comes the risk of harm.
Org safeguards by prompting for user's permission before executing any
code in the source block.  To customize this safeguard, or disable it,
see [[*Code Evaluation and Security Issues]].

*** How to evaluate source code
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Org captures the results of the code block evaluation and inserts them
in the Org file, right after the code block.  The insertion point is
after a newline and the =RESULTS= keyword.  Org creates the =RESULTS=
keyword if one is not already there.  More details in [[*Results of
Evaluation]].

By default, Org enables only Emacs Lisp code blocks for execution.
See [[*Languages]] to enable other languages.

#+kindex: C-c C-c
#+kindex: C-c C-v e
#+findex: org-babel-execute-src-block
Org provides many ways to execute code blocks.  {{{kbd(C-c C-c)}}} or
{{{kbd(C-c C-v e)}}} with the point on a code block[fn:: The option
~org-babel-no-eval-on-ctrl-c-ctrl-c~ can be used to remove code
evaluation from the {{{kbd(C-c C-c)}}} key binding.] calls the
~org-babel-execute-src-block~ function, which executes the code in the
block, collects the results, and inserts them in the buffer.

#+cindex: @samp{CALL}, keyword
#+vindex: org-babel-inline-result-wrap
By calling a named code block[fn:48] from an Org mode buffer or
a table.  Org can call the named code blocks from the current Org mode
buffer or from the "Library of Babel" (see [[*Library of Babel]]).

The syntax for =CALL= keyword is:

#+begin_example
,#+CALL: <name>(<arguments>)
,#+CALL: <name>[<inside header arguments>](<arguments>) <end header arguments>
#+end_example

The syntax for inline named code blocks is:

#+begin_example
... call_<name>(<arguments>) ...
... call_<name>[<inside header arguments>](<arguments>)[<end header arguments>] ...
#+end_example

When inline syntax is used, the result is wrapped based on the
variable ~org-babel-inline-result-wrap~, which by default is set to
~"=%s="~ to produce verbatim text suitable for markup.

- =<name>= ::

  This is the name of the code block (see [[*Structure of Code Blocks]])
  to be evaluated in the current document.  If the block is located in
  another file, start =<name>= with the file name followed by
  a colon.  For example, in order to execute a block named =clear-data=
  in =file.org=, you can write the following:

  : #+CALL: file.org:clear-data()

- =<arguments>= ::

  Org passes arguments to the code block using standard function call
  syntax.  For example, a =#+CALL:= line that passes =4= to a code
  block named =double=, which declares the header argument =:var n=2=,
  would be written as:

  : #+CALL: double(n=4)

  #+texinfo: @noindent
  Note how this function call syntax is different from the header
  argument syntax.

- =<inside header arguments>= ::

  Org passes inside header arguments to the named code block using the
  header argument syntax.  Inside header arguments apply to code block
  evaluation.  For example, =[:results output]= collects results
  printed to stdout during code execution of that block.  Note how
  this header argument syntax is different from the function call
  syntax.

- =<end header arguments>= ::

  End header arguments affect the results returned by the code block.
  For example, =:results html= wraps the results in a =#+BEGIN_EXPORT
  html= block before inserting the results in the Org buffer.

*** Limit code block evaluation
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: @samp{eval}, header argument
#+cindex: control code block evaluation
The =eval= header argument can limit evaluation of specific code
blocks and =CALL= keyword.  It is useful for protection against
evaluating untrusted code blocks by prompting for a confirmation.

- =yes= ::

  Org always evaluates the source code without asking permission.

- =never= or =no= ::

  Org never evaluates the source code.

- =query= ::

  Org prompts the user for permission to evaluate the source code.

- =never-export= or =no-export= ::

  Org does not evaluate the source code when exporting, yet the user
  can evaluate it interactively.

- =query-export= ::

  Org prompts the user for permission to evaluate the source code
  during export.

If =eval= header argument is not set, then Org determines whether to
evaluate the source code from the ~org-confirm-babel-evaluate~
variable (see [[*Code Evaluation and Security Issues]]).

*** Cache results of evaluation
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: @samp{cache}, header argument
#+cindex: cache results of code evaluation
The =cache= header argument is for caching results of evaluating code
blocks.  Caching results can avoid re-evaluating a code block that
have not changed since the previous run.  To benefit from the cache
and avoid redundant evaluations, the source block must have a result
already present in the buffer, and neither the header
arguments---including the value of =var= references---nor the text of
the block itself has changed since the result was last computed.  This
feature greatly helps avoid long-running calculations.  For some edge
cases, however, the cached results may not be reliable.

The caching feature is best for when code blocks are pure functions,
that is functions that return the same value for the same input
arguments (see [[*Environment of a Code Block]]), and that do not have
side effects, and do not rely on external variables other than the
input arguments.  Functions that depend on a timer, file system
objects, and random number generators are clearly unsuitable for
caching.

A note of warning: when =cache= is used in a session, caching may
cause unexpected results.

When the caching mechanism tests for any source code changes, it does
not expand noweb style references (see [[*Noweb Reference Syntax]]).

The =cache= header argument can have one of two values: =yes= or =no=.

- =no= ::

  Default.  No caching of results; code block evaluated every time.

- =yes= ::

  Whether to run the code or return the cached results is determined
  by comparing the SHA1 hash value of the combined code block and
  arguments passed to it.  This hash value is packed on the
  =#+RESULTS:= line from previous evaluation.  When hash values match,
  Org does not evaluate the code block.  When hash values mismatch,
  Org evaluates the code block, inserts the results, recalculates the
  hash value, and updates =#+RESULTS:= line.

In this example, both functions are cached.  But =caller= runs only if
the result from =random= has changed since the last run.

# +1 here is to work around Emacs bug#59293.
# Otherwise, (1) is recognized as footnote reference by info.el.
#+begin_example
,#+NAME: random
,#+BEGIN_SRC R :cache yes
  runif(+1)
,#+END_SRC

,#+RESULTS[a2a72cd647ad44515fab62e144796432793d68e1]: random
0.4659510825295

,#+NAME: caller
,#+BEGIN_SRC emacs-lisp :var x=random :cache yes
  x
,#+END_SRC

,#+RESULTS[bec9c8724e397d5df3b696502df3ed7892fc4f5f]: caller
0.254227238707244
#+end_example

** Results of Evaluation
:PROPERTIES:
:DESCRIPTION: Choosing a results type, post-processing...
:END:
#+cindex: code block, results of evaluation
#+cindex: source code, results of evaluation

#+cindex: @samp{results}, header argument
How Org handles results of a code block execution depends on many
header arguments working together.  The primary determinant, however,
is the =results= header argument.  It accepts four classes of options.
Each code block can take only one option per class:

- Collection ::

  For how the results should be collected from the code block;

- Type ::

  For which type of result the code block will return; affects how Org
  processes and inserts results in the Org buffer;

- Format ::

  For the result; affects how Org processes results;

- Handling ::

  For inserting results once they are properly formatted.

*** Collection
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Collection options specify the results.  Choose one of the options;
they are mutually exclusive.

- =value= ::

  Default for most Babel libraries[fn:48].  Functional mode.  Org
  gets the value by wrapping the code in a function definition in the
  language of the source block.  That is why when using =:results
  value=, code should execute like a function and return a value.  For
  languages like Python, an explicit ~return~ statement is mandatory
  when using =:results value=.  Result is the value returned by the
  last statement in the code block.

  When evaluating the code block in a session (see [[*Environment of
  a Code Block]]), Org passes the code to an interpreter running as an
  interactive Emacs inferior process.  Org gets the value from the
  source code interpreter's last statement output.  Org has to use
  language-specific methods to obtain the value.  For example, from
  the variable ~_~ in Ruby, and the value of ~.Last.value~ in R.

- =output= ::

  Scripting mode.  Org passes the code to an external process running
  the interpreter.  Org returns the contents of the standard output
  stream as text results.

  When using a session, Org passes the code to the interpreter running
  as an interactive Emacs inferior process.  Org concatenates any text
  output from the interpreter and returns the collection as a result.

*** Type
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Type tells what result types to expect from the execution of the code
block.  Choose one of the options; they are mutually exclusive.

The default behavior is to automatically determine the result type.
The result type detection depends on the code block language, as
described in the documentation for individual languages.  See
[[*Languages]].

#+attr_texinfo: :sep ,
- =table=, =vector= ::

  Interpret the results as an Org table.  If the result is a single
  value, create a table with one row and one column.  Usage example:
  =:results value table=.

  #+cindex: @samp{hlines}, header argument
  In-between each table row or below the table headings, sometimes
  results have horizontal lines, which are also known as "hlines".
  The =hlines= argument with the default =no= value strips such lines
  from the input table.  For most code, this is desirable, or else
  those =hline= symbols raise unbound variable errors.  A =yes=
  accepts such lines, as demonstrated in the following example.

  #+begin_example
  ,#+NAME: many-cols
  | a | b | c |
  |---+---+---|
  | d | e | f |
  |---+---+---|
  | g | h | i |

  ,#+NAME: no-hline
  ,#+BEGIN_SRC python :var tab=many-cols :hlines no
    return tab
  ,#+END_SRC

  ,#+RESULTS: no-hline
  | a | b | c |
  | d | e | f |
  | g | h | i |

  ,#+NAME: hlines
  ,#+BEGIN_SRC python :var tab=many-cols :hlines yes
    return tab
  ,#+END_SRC

  ,#+RESULTS: hlines
  | a | b | c |
  |---+---+---|
  | d | e | f |
  |---+---+---|
  | g | h | i |
  #+end_example

- =list= ::

  Interpret the results as an Org list.  If the result is a single
  value, create a list of one element.

- =scalar=, =verbatim= ::

  Interpret literally and insert as quoted text.  Do not create
  a table.  Usage example: =:results value verbatim=.

- =file= ::

  Interpret as a filename.  Save the results of execution of the code
  block to that file, then insert a link to it.  You can control both
  the filename and the description associated to the link.

  #+cindex: @samp{file}, header argument
  #+cindex: @samp{output-dir}, header argument
  Org first tries to generate the filename from the value of the
  =file= header argument and the directory specified using the
  =output-dir= header arguments.  If =output-dir= is not specified,
  Org assumes it is the current directory.

  #+begin_example
  ,#+BEGIN_SRC asymptote :results value file :file circle.pdf :output-dir img/
    size(2cm);
    draw(unitcircle);
  ,#+END_SRC
  #+end_example

  #+cindex: @samp{file-ext}, header argument
  If =file= header argument is missing, Org generates the base name of
  the output file from the name of the code block, and its extension
  from the =file-ext= header argument.  In that case, both the name
  and the extension are mandatory.

  #+begin_example
  ,#+name: circle
  ,#+BEGIN_SRC asymptote :results value file :file-ext pdf
    size(2cm);
    draw(unitcircle);
  ,#+END_SRC
  #+end_example

  #+cindex: @samp{file-desc}, header argument
  The =file-desc= header argument defines the description (see [[*Link
  Format]]) for the link.  If =file-desc= is present but has no value,
  the =file= value is used as the link description.  When this
  argument is not present, the description is omitted.  If you want to
  provide the =file-desc= argument but omit the description, you can
  provide it with an empty vector (i.e., :file-desc []).

  #+cindex: @samp{sep}, header argument
  By default, Org assumes that a table written to a file has
  TAB-delimited output.  You can choose a different separator with
  the =sep= header argument.

  #+cindex: @samp{file-mode}, header argument
  The =file-mode= header argument defines the file permissions.  To
  make it executable, use =:file-mode (identity #o755)=.

  #+begin_example
  ,#+BEGIN_SRC shell :results file :file script.sh :file-mode (identity #o755)
    echo "#!/bin/bash"
    echo "echo Hello World"
  ,#+END_SRC
  #+end_example

*** Format
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Format pertains to the type of the result returned by the code block.
Choose one of the options; they are mutually exclusive.  The default
follows from the type specified above.

#+attr_texinfo: :sep ,
- =code= ::

  Result enclosed in a code block.  Useful for parsing.  Usage
  example: =:results value code=.

- =drawer= ::

  Result wrapped in a =RESULTS= drawer.  Useful for containing =raw=
  or =org= results for later scripting and automated processing.
  Usage example: =:results value drawer=.

- =html= ::

  Results enclosed in a =BEGIN_EXPORT html= block.  Usage example:
  =:results value html=.

- =latex= ::

  Results enclosed in a =BEGIN_EXPORT latex= block.  Usage example:
  =:results value latex=.

- =link=, =graphics= ::

  When used along with =file= type, the result is a link to the file
  specified in =:file= header argument.  However, unlike plain =file=
  type, code block output is not written to the disk.  The block is
  expected to generate the file by its side-effects only, as in the
  following example:

  #+begin_example
  ,#+begin_src shell :results file link :file "org-mode-unicorn.svg"
    wget -c "https://orgmode.org/resources/img/org-mode-unicorn.svg"
  ,#+end_src

  ,#+RESULTS:
  [[file:org-mode-unicorn.svg]]
  #+end_example

- =org= ::

  Results enclosed in a =BEGIN_SRC org= block.  For comma-escape,
  either {{{kbd(TAB)}}} in the block, or export the file.  Usage
  example: =:results value org=.

- =pp= ::

  Result converted to pretty-print source code.  Enclosed in a code
  block.  Languages supported: Emacs Lisp, Python, and Ruby.  Usage
  example: =:results value pp=.

- =raw= ::

  Interpreted as raw Org mode.  Inserted directly into the buffer.
  Aligned if it is a table.  Usage example: =:results value raw=.

#+cindex: @samp{wrap}, header argument
The =wrap= header argument unconditionally marks the results block by
appending strings to =#+BEGIN_= and =#+END_=.  If no string is
specified, Org wraps the results in a =#+BEGIN_results=
... =#+END_results= block.  It takes precedent over the =results=
value listed above.  E.g.,

#+begin_example
,#+BEGIN_SRC emacs-lisp :results html :wrap EXPORT markdown
"<blink>Welcome back to the 90's</blink>"
,#+END_SRC

,#+RESULTS:
,#+BEGIN_EXPORT markdown
<blink>Welcome back to the 90's</blink>
,#+END_EXPORT
#+end_example

*** Handling
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Handling options after collecting the results.  Choose one of the
options; they are mutually exclusive.

- =replace= ::

  Default.  Insert results in the Org buffer.  Remove previous
  results.  Usage example: =:results output replace=.

- =silent= ::

  Do not insert results in the Org mode buffer, but echo them in the
  minibuffer.  Usage example: =:results output silent=.

- =none= ::

  Compute results, but do not do anything with them.  No inserting in
  the Org mode buffer nor echo them in the minibuffer.  The results
  can still be used when referenced from another code block.
  Usage example: =:results none=.

- =discard= ::

  Ignore the results completely.  This option is similar to =none=,
  but no processing is performed on the return value.  Calling the
  code block programmatically (see [[*How to evaluate source code]]) or by
  reference (see [[*Passing arguments]] and [[*Noweb Reference Syntax]]) will
  always yield nil.

- =append= ::

  Append results to the Org buffer.  Latest results are at the bottom.
  Does not remove previous results.  Usage example: =:results output
  append=.

- =prepend= ::

  Prepend results to the Org buffer.  Latest results are at the top.
  Does not remove previous results.  Usage example: =:results output
  prepend=.

*** Post-processing
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: @samp{post}, header argument
#+cindex: @samp{*this*}, in @samp{post} header argument
The =post= header argument is for post-processing results from block
evaluation.  When =post= has any value, Org binds the results to
~*this*~ variable for easy passing to =var= header argument
specifications (see [[*Environment of a Code Block]]).  That makes results
available to other code blocks, or even for direct Emacs Lisp code
execution.

The following two examples illustrate =post= header argument in
action.  The first one shows how to attach an =ATTR_LATEX= keyword
using =post=.

#+begin_example
,#+NAME: attr_wrap
,#+BEGIN_SRC sh :var data="" :var width="\\textwidth" :results output
  echo "#+ATTR_LATEX: :width $width"
  echo "$data"
,#+END_SRC

,#+HEADER: :file /tmp/it.png
,#+BEGIN_SRC dot :post attr_wrap(width="5cm", data=*this*) :results drawer
  digraph{
          a -> b;
          b -> c;
          c -> a;
  }
,#+end_src

,#+RESULTS:
:RESULTS:
,#+ATTR_LATEX :width 5cm
[[file:/tmp/it.png]]
:END:
#+end_example

The second example shows use of =colnames= header argument in =post=
to pass data between code blocks.

#+begin_example
,#+NAME: round-tbl
,#+BEGIN_SRC emacs-lisp :var tbl="" fmt="%.3f"
  (mapcar (lambda (row)
            (mapcar (lambda (cell)
                      (if (numberp cell)
                          (format fmt cell)
                        cell))
                    row))
          tbl)
,#+end_src

,#+BEGIN_SRC R :colnames yes :post round-tbl[:colnames yes](*this*)
  set.seed(42)
  data.frame(foo=rnorm(1))
,#+END_SRC

,#+RESULTS:
|   foo |
|-------|
| 1.371 |
#+end_example

** Exporting Code Blocks
:PROPERTIES:
:DESCRIPTION: Export contents and/or results.
:END:
#+cindex: code block, exporting
#+cindex: source code, exporting

It is possible to export the /code/ of code blocks, the /results/ of
code block evaluation, /both/ the code and the results of code block
evaluation, or /none/.  Org defaults to exporting /code/ for most
languages and /results/ for inline code blocks.  For some languages,
such as ditaa, Org defaults to /results/ both in ordinary source
blocks and in inline source blocks.  To export just the body of code
blocks, see [[*Literal Examples]].  To selectively export subtrees of an
Org document, see [[*Exporting]].

#+cindex: @samp{exports}, header argument
The =exports= header argument is to specify if that part of the Org
file is exported to, say, HTML or LaTeX formats.

- =code= ::

  The default.  The body of code is included into the exported file.
  Example: =:exports code=.

- =results= ::

  The results of evaluation of the code is included in the exported
  file.  Example: =:exports results=.

- =both= ::

  Both the code and results of evaluation are included in the exported
  file.  Example: =:exports both=.

- =none= ::

  Neither the code nor the results of evaluation is included in the
  exported file.  Whether the code is evaluated at all depends on
  other options.  Example: =:exports none=.

If a source block is named using =NAME= keyword, the same name will be
assigned to the results of evaluation.  This way, fuzzy links pointing
to the named source blocks exported using =:exports results= will
remain valid and point to the results of evaluation.

Results of evaluation of a named block can also be explicitly named
using a separate =NAME= keyword.  The name value set via =NAME=
keyword will be preferred over the parent source block.

: #+NAME: code name
: #+BEGIN_SRC emacs-lisp :exports both value
: (+ 1 2)
: #+END_SRC
:
: #+NAME: results name
: #+RESULTS: code name
: 3
:
: This [[code name][link]] will point to the code block.
: Another [[results name][link]] will point to the results.

Explicit setting of the result name may be necessary when a named code
block is exported using =:exports both=.  Links to such block may
arbitrarily point either to the code block or to its results when
results do not have a distinct name.

Note that all the links pointing to a source block exported using
=:exports none= will be broken.  This will make export process fail,
unless broken links are allowed during export (see [[*Export Settings]]).

#+vindex: org-export-use-babel
To stop Org from evaluating code blocks to speed exports, use the
header argument =:eval never-export= (see [[*Evaluating Code Blocks]]).
To stop Org from evaluating code blocks for greater security, set the
~org-export-use-babel~ variable to ~nil~, but understand that header
arguments will have no effect.

Turning off evaluation comes in handy when batch processing.  For
example, markup languages for wikis, which have a high risk of
untrusted code.  Stopping code block evaluation also stops evaluation
of all header arguments of the code block.  This may not be desirable
in some circumstances.  So during export, to allow evaluation of just
the header arguments but not any code evaluation in the source block,
set =:eval never-export= (see [[*Evaluating Code Blocks]]).

Org never evaluates code blocks in commented subtrees when exporting
(see [[*Comment Lines]]).  On the other hand, Org does evaluate code
blocks in subtrees excluded from export (see [[*Export Settings]]).

** Extracting Source Code
:PROPERTIES:
:DESCRIPTION: Create pure source code files.
:END:
#+cindex: tangling
#+cindex: source code, extracting
#+cindex: code block, extracting source code

Extracting source code from code blocks is a basic task in literate
programming.  Org has features to make this easy.  In literate
programming parlance, documents on creation are /woven/ with code and
documentation, and on export, the code is tangled for execution by
a computer.  Org facilitates weaving and tangling for producing,
maintaining, sharing, and exporting literate programming documents.
Org provides extensive customization options for extracting source
code.

When Org tangles code blocks, it expands, merges, and transforms them.
Then Org recomposes them into one or more separate files, as
configured through the options.  During this tangling process, Org
expands variables in the source code, and resolves any noweb style
references (see [[*Noweb Reference Syntax]]).

*** Header arguments
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+cindex: @samp{tangle}, header argument
The =tangle= header argument specifies if the code block is exported
to source file(s).

- =yes= ::

  Export the code block to source file.  The file name for the source
  file is derived from the name of the Org file, and the file
  extension is derived from the source code language identifier.
  Example: =:tangle yes=.

- =no= ::

  The default.  Do not extract the code in a source code file.
  Example: =:tangle no=.

- {{{var(FILENAME)}}} ::

  Export the code block to source file whose file name is derived from
  any string passed to the =tangle= header argument.  Org derives the
  file name as being relative to the directory of the Org file's
  location.  Example: =:tangle FILENAME=.

#+cindex: @samp{mkdirp}, header argument
The =mkdirp= header argument creates parent directories for tangled
files if the directory does not exist.  A =yes= value enables
directory creation whereas =no= inhibits it.

#+cindex: @samp{comments}, header argument
The =comments= header argument controls inserting comments into
tangled files.  These are above and beyond whatever comments may
already exist in the code block.

- =no= ::

  The default.  Do not insert any extra comments during tangling.

- =link= ::

  Wrap the code block in comments.  Include links pointing back to the
  place in the Org file from where the code was tangled.

- =yes= ::

  Kept for backward compatibility; same as =link=.

- =org= ::

  Nearest headline text from Org file is inserted as comment.  The
  exact text that is inserted is picked from the leading context of
  the source block.

- =both= ::

  Includes both =link= and =org= options.

- =noweb= ::

  Includes =link= option, expands noweb references (see [[*Noweb
  Reference Syntax]]), and wraps them in link comments inside the body
  of the code block.

#+cindex: @samp{padline}, header argument
The =padline= header argument controls insertion of newlines to pad
source code in the tangled file.

- =yes= ::

  Default.  Insert a newline before and after each code block in the
  tangled file.

- =no= ::

  Do not insert newlines to pad the tangled code blocks.

#+cindex: @samp{shebang}, header argument
The =shebang= header argument can turn results into executable script
files.  By setting it to a string value---for example, =:shebang
"#!/bin/bash"=---Org inserts that string as the first line of the
tangled file that the code block is extracted to.  Org then turns on
the tangled file's executable permission.

#+cindex: @samp{tangle-mode}, header argument
The =tangle-mode= header argument specifies what permissions to set
for tangled files by ~set-file-modes~.  Permissions are given by an
octal value, which can be provided calling the ~identity~ function on
an elisp octal value. For instance, to create a read-only file one may
use =:tangle-mode (identity #o444)=. To reduce the verbosity required,
a octal shorthand is defined, =oXXX= (=o= for octal). Using this, our
read-only example is =:tangle-mode o444=. Omitting the =o= prefix will
cause the argument to be interpreted as an integer, which can lead to
unexpected results (=444= is the same as =o674=).
Two other shorthands are recognized, ls-style strings like
=rw-r--r--=, and chmod-style permissions like =g+w=.
Note that chmod-style permissions are based on
~org-babel-tangle-default-file-mode~, which is =#o544= by default.

When =:tangle-mode= and =:shebang= are both specified, the give
=:tangle-mode= will override the permissions from =:shebang=. When
multiple source code blocks tangle to a single file with conflicting
=:tangle-mode= header arguments, Org's behavior is undefined.

#+cindex: @samp{no-expand}, header argument
By default Org expands code blocks during tangling.  The =no-expand=
header argument turns off such expansions.  Note that one side-effect
of expansion by ~org-babel-expand-src-block~ also assigns values (see
[[*Environment of a Code Block]]) to variables.  Expansions also replace
noweb references with their targets (see [[*Noweb Reference Syntax]]).
Some of these expansions may cause premature assignment, hence this
option.  This option makes a difference only for tangling.  It has no
effect when exporting since code blocks for execution have to be
expanded anyway.

*** Functions
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- ~org-babel-tangle~ ::

  #+findex: org-babel-tangle
  #+kindex: C-c C-v t
  Tangle the current file.  Bound to {{{kbd(C-c C-v t)}}}.

  With prefix argument only tangle the current code block.

- ~org-babel-tangle-file~ ::

  #+findex: org-babel-tangle-file
  #+kindex: C-c C-v f
  Choose a file to tangle.  Bound to {{{kbd(C-c C-v f)}}}.

*** Tangle hooks
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- ~org-babel-pre-tangle-hook~ ::

  #+vindex: org-babel-pre-tangle-hook
  This hook is run before the tangle process begins.  The active
  buffer is buffer to be tangled.

- ~org-babel-tangle-body-hook~ ::

  #+vindex: org-babel-tangle-body-hook
  This hook is run from a temporary buffer containing expanded code of
  every tangled code block.  The hook can modify the expanded code as
  needed.  The contents of the current buffer will be used as actual
  code block expansion.

- ~org-babel-post-tangle-hook~ ::

  #+vindex: org-babel-post-tangle-hook
  This hook is run from within code files tangled by
  ~org-babel-tangle~, making it suitable for post-processing,
  compilation, and evaluation of code in the tangled files.

- ~org-babel-tangle-finished-hook~ ::
  #+vindex: org-babel-tangle-finished-hook
  This hook is run after post-tangle hooks, in the original buffer.

*** Jumping between code and Org
:PROPERTIES:
:UNNUMBERED: notoc
:END:

#+findex: org-babel-tangle-jump-to-org
Debuggers normally link errors and messages back to the source code.
But for tangled files, we want to link back to the Org file, not to
the tangled source file.  To make this extra jump, Org uses
~org-babel-tangle-jump-to-org~ function with two additional source
code block header arguments:

1. Set =padline= to true---this is the default setting.
2. Set =comments= to =link=, which makes Org insert links to the Org
   file.

** Languages
:PROPERTIES:
:DESCRIPTION: List of supported code block languages.
:END:
#+cindex: babel, languages
#+cindex: source code, languages
#+cindex: code block, languages

Code blocks in dozens of languages are supported.  See Worg website
for [[https://orgmode.org/worg/org-contrib/babel/languages/index.html][language specific documentation]].

#+vindex: org-babel-load-languages
By default, only Emacs Lisp is enabled for evaluation.  To enable or
disable other languages, customize the ~org-babel-load-languages~
variable either through the Emacs customization interface, or by
adding code to the init file as shown next.

In this example, evaluation is disabled for Emacs Lisp, and enabled
for R.

#+begin_src emacs-lisp
(org-babel-do-load-languages
 'org-babel-load-languages
 '((emacs-lisp . nil)
   (R . t)))
#+end_src

Note that this is not the only way to enable a language.  Org also
enables languages when loaded with ~require~ statement.  For example,
the following enables execution of Clojure code blocks:

#+begin_src emacs-lisp
(require 'ob-clojure)
#+end_src

** Editing Source Code
:PROPERTIES:
:DESCRIPTION: Language major-mode editing.
:END:
#+cindex: code block, editing
#+cindex: source code, editing

#+kindex: C-c '
Use {{{kbd(C-c ')}}} to edit the current code block.  It opens a new
major mode edit buffer containing the body of the source code block,
ready for any edits.  Use {{{kbd(C-c ')}}} again to close the buffer
and return to the Org buffer.

#+kindex: C-x C-s
#+vindex: org-edit-src-auto-save-idle-delay
#+cindex: auto-save, in code block editing
{{{kbd(C-x C-s)}}} saves the buffer and updates the contents of the
Org buffer.  Set ~org-edit-src-auto-save-idle-delay~ to save the base
buffer after a certain idle delay time.  Set
~org-edit-src-turn-on-auto-save~ to auto-save this buffer into
a separate file using Auto-save mode.

While editing the source code in the major mode, the Org Src minor
mode remains active.  It provides these customization variables as
described below.  For even more variables, look in the customization
group ~org-edit-structure~.

- ~org-src-lang-modes~ ::

  #+vindex: org-src-lang-modes
  If an Emacs major-mode named ~<LANG>-mode~ exists, where
  {{{var(<LANG>)}}} is the language identifier from code block's
  header line, then the edit buffer uses that major mode.  Use this
  variable to arbitrarily map language identifiers to major modes.

- ~org-src-window-setup~ ::

  #+vindex: org-src-window-setup
  For specifying Emacs window arrangement when the new edit buffer is
  created.

- ~org-src-preserve-indentation~ ::

  #+cindex: indentation, in code blocks
  #+vindex: org-src-preserve-indentation
  Default is ~nil~.  Source code is indented.  This indentation
  applies during export or tangling, and depending on the context, may
  alter leading spaces and tabs.  When non-~nil~, source code is
  aligned with the leftmost column.  No lines are modified during
  export or tangling, which is very useful for white-space sensitive
  languages, such as Python.

- ~org-src-ask-before-returning-to-edit-buffer~ ::

  #+vindex: org-src-ask-before-returning-to-edit-buffer
  When ~nil~, Org returns to the edit buffer without further prompts.
  The default prompts for a confirmation.

#+vindex: org-src-fontify-natively
#+vindex: org-src-block-faces
Set ~org-src-fontify-natively~ to non-~nil~ to turn on native code
fontification in the /Org/ buffer.  Fontification of code blocks can
give visual separation of text and code on the display page.  To
further customize the appearance of ~org-block~ for specific
languages, customize ~org-src-block-faces~.  The following example
shades the background of regular blocks, and colors source blocks only
for Python and Emacs Lisp languages.

#+begin_src emacs-lisp
(require 'color)
(set-face-attribute 'org-block nil :background
                    (color-darken-name
                     (face-attribute 'default :background) 3))

(setq org-src-block-faces '(("emacs-lisp" (:background "#EEE2FF"))
                            ("python" (:background "#E5FFB8"))))
#+end_src

** Noweb Reference Syntax
:PROPERTIES:
:DESCRIPTION: Literate programming in Org mode.
:END:
#+cindex: code block, noweb reference
#+cindex: syntax, noweb
#+cindex: source code, noweb reference

#+cindex: @samp{noweb-ref}, header argument
Source code blocks can include references to other source code blocks,
using a noweb[fn:: For noweb literate programming details, see
https://www.cs.tufts.edu/~nr/noweb/.] style syntax:

: <<CODE-BLOCK-ID>>

#+texinfo: @noindent
where {{{var(CODE-BLOCK-ID)}}} refers to either the =NAME= of a single
source code block, or a collection of one or more source code blocks
sharing the same =noweb-ref= header argument (see [[*Using Header
Arguments]]).  Org can replace such references with the source code of
the block or blocks being referenced, or, in the case of a single
source code block named with =NAME=, with the results of an evaluation
of that block.

#+cindex: @samp{noweb}, header argument
The =noweb= header argument controls expansion of noweb syntax
references.  Expansions occur when source code blocks are evaluated,
tangled, or exported.

- =no= ::

  Default.  No expansion of noweb syntax references in the body of the
  code when evaluating, tangling, or exporting.

- =yes= ::

  Expansion of noweb syntax references in the body of the code block
  when evaluating, tangling, or exporting.

- =tangle= ::

  Expansion of noweb syntax references in the body of the code block
  when tangling.  No expansion when evaluating or exporting.

- =strip-tangle= ::

  Expansion of noweb syntax references in the body of the code block
  when evaluating or exporting.  Removes noweb syntax references
  when exporting.

- =no-export= ::

  Expansion of noweb syntax references in the body of the code block
  when evaluating or tangling.  No expansion when exporting.

- =strip-export= ::

  Expansion of noweb syntax references in the body of the code block
  when expanding prior to evaluating or tangling.  Removes noweb
  syntax references when exporting.

- =eval= ::

  Expansion of noweb syntax references in the body of the code block
  only before evaluating.

In the most simple case, the contents of a single source block is
inserted within other blocks.  Thus, in following example,

#+begin_example
,#+NAME: initialization
,#+BEGIN_SRC emacs-lisp
  (setq sentence "Never a foot too far, even.")
,#+END_SRC

,#+BEGIN_SRC emacs-lisp :noweb yes
  <<initialization>>
  (reverse sentence)
,#+END_SRC
#+end_example

#+texinfo: @noindent
the second code block is expanded as

#+begin_example
,#+BEGIN_SRC emacs-lisp :noweb yes
  (setq sentence "Never a foot too far, even.")
  (reverse sentence)
,#+END_SRC
#+end_example

You may also include the contents of multiple blocks sharing a common
=noweb-ref= header argument, which can be set at the file, subtree,
or code block level.  In the example Org file shown next, the body of
the source code in each block is extracted for concatenation to a pure
code file when tangled.

#+begin_example
,#+BEGIN_SRC sh :tangle yes :noweb yes :shebang #!/bin/sh
  <<fullest-disk>>
,#+END_SRC
,* the mount point of the fullest disk
  :PROPERTIES:
  :header-args: :noweb-ref fullest-disk
  :END:

,** query all mounted disks
,#+BEGIN_SRC sh
  df \
,#+END_SRC

,** strip the header row
,#+BEGIN_SRC sh
  |sed '1d' \
,#+END_SRC

,** output mount point of fullest disk
,#+BEGIN_SRC sh
  |awk '{if (u < +$5) {u = +$5; m = $6}} END {print m}'
,#+END_SRC
#+end_example

#+cindex: @samp{noweb-sep}, header argument
By default a newline separates each noweb reference concatenation.  To
use a different separator, edit the =noweb-sep= header argument.

Alternatively, Org can include the results of evaluation of a single
code block rather than its body.  Evaluation occurs when parentheses,
possibly including arguments, are appended to the code block name, as
shown below.

: <<NAME(optional arguments)>>

Note that in this case, a code block name set by =NAME= keyword is
required; the reference set by =noweb-ref= will not work when
evaluation is desired.

Here is an example that demonstrates how the exported content changes
when noweb style references are used with parentheses versus without.
Given:

#+begin_example
,#+NAME: some-code
,#+BEGIN_SRC python :var num=0 :results output :exports none
  print(num*10)
,#+END_SRC
#+end_example

#+texinfo: @noindent
this code block:

#+begin_example
,#+BEGIN_SRC text :noweb yes
  <<some-code>>
,#+END_SRC
#+end_example

#+texinfo: @noindent
expands to:

: print(num*10)

Below, a similar noweb style reference is used, but with parentheses,
while setting a variable =num= to 10:

#+begin_example
,#+BEGIN_SRC text :noweb yes
  <<some-code(num=10)>>
,#+END_SRC
#+end_example

#+texinfo: @noindent
Note that the expansion now contains the results of the code block
=some-code=, not the code block itself:

: 100

Noweb insertions honor prefix characters that appear before the noweb
syntax reference.  This behavior is illustrated in the following
example.  Because the =<<example>>= noweb reference appears behind the
SQL comment syntax, each line of the expanded noweb reference is
commented.  With:

#+begin_example
,#+NAME: example
,#+BEGIN_SRC text
  this is the
  multi-line body of example
,#+END_SRC
#+end_example

#+texinfo: @noindent
this code block:

#+begin_example
,#+BEGIN_SRC sql :noweb yes
 ---<<example>>
,#+END_SRC
#+end_example

#+texinfo: @noindent
expands to:

#+begin_example
,#+BEGIN_SRC sql :noweb yes
 ---this is the
 ---multi-line body of example
,#+END_SRC
#+end_example

Since this change does not affect noweb replacement text without
newlines in them, inline noweb references are acceptable.

This feature can also be used for management of indentation in
exported code snippets.  With:

#+begin_example
,#+NAME: if-true
,#+BEGIN_SRC python :exports none
  print('do things when true')
,#+end_src

,#+name: if-false
,#+begin_src python :exports none
  print('do things when false')
,#+end_src
#+end_example

#+texinfo: @noindent
this code block:

#+begin_example
,#+begin_src python :noweb yes :results output
  if true:
      <<if-true>>
  else:
      <<if-false>>
,#+end_src
#+end_example

#+texinfo: @noindent
expands to:

#+begin_example
if true:
    print('do things when true')
else:
    print('do things when false')
#+end_example

This prefix behavior can be turned off in a block by setting the
=noweb-prefix= header argument to =no=, as in:

#+begin_example
,#+BEGIN_SRC elisp :noweb-prefix no
  (setq example-data "<<example>>")
,#+END_SRC
#+end_example

#+texinfo: @noindent
which expands to:

#+begin_example
(setq example-data "this is the
multi-line body of example")
#+end_example

When in doubt about the outcome of a source code block expansion, you
can preview the results with the following command:

- {{{kbd(C-c C-v v)}}} or {{{kbd(C-c C-v C-v)}}} (~org-babel-expand-src-block~) ::

  #+findex: org-babel-expand-src-block
  #+kindex: C-c C-v v
  #+kindex: C-c C-v C-v
  Expand the current source code block according to its header
  arguments and pop open the results in a preview buffer.

** Library of Babel
:PROPERTIES:
:DESCRIPTION: Use and contribute to a library of useful code blocks.
:END:
#+cindex: babel, library of
#+cindex: source code, library
#+cindex: code block, library

The "Library of Babel" is a collection of code blocks.  Like
a function library, these code blocks can be called from other Org
files.  A collection of useful code blocks is available on [[https://orgmode.org/worg/library-of-babel.html][Worg]].  For
remote code block evaluation syntax, see [[*Evaluating Code Blocks]].

#+kindex: C-c C-v i
#+findex: org-babel-lob-ingest
For any user to add code to the library, first save the code in
regular code blocks of an Org file, and then load the Org file with
~org-babel-lob-ingest~, which is bound to {{{kbd(C-c C-v i)}}}.

** Key bindings and Useful Functions
:PROPERTIES:
:DESCRIPTION: Work quickly with code blocks.
:END:
#+cindex: code block, key bindings

Many common Org mode key sequences are re-bound depending on
the context.

Active key bindings in code blocks:

#+kindex: C-c C-c
#+findex: org-babel-execute-src-block
#+kindex: C-c C-o
#+findex: org-babel-open-src-block-result
#+kindex: M-UP
#+findex: org-babel-load-in-session
#+kindex: M-DOWN
#+findex: org-babel-pop-to-session
#+attr_texinfo: :columns 0.2 0.55
| Key binding        | Function                          |
|--------------------+-----------------------------------|
| {{{kbd(C-c C-c)}}} | ~org-babel-execute-src-block~     |
| {{{kbd(C-c C-o)}}} | ~org-babel-open-src-block-result~ |
| {{{kbd(M-UP)}}}    | ~org-babel-load-in-session~       |
| {{{kbd(M-DOWN)}}}  | ~org-babel-pop-to-session~        |

Active key bindings in Org mode buffer:

#+kindex: C-c C-v p
#+kindex: C-c C-v C-p
#+kindex: C-c C-v n
#+kindex: C-c C-v C-n
#+kindex: C-c C-v e
#+kindex: C-c C-v C-e
#+kindex: C-c C-v o
#+kindex: C-c C-v C-o
#+kindex: C-c C-v v
#+kindex: C-c C-v C-v
#+kindex: C-c C-v u
#+kindex: C-c C-v C-u
#+kindex: C-c C-v g
#+kindex: C-c C-v C-g
#+kindex: C-c C-v r
#+kindex: C-c C-v C-r
#+kindex: C-c C-v b
#+kindex: C-c C-v C-b
#+kindex: C-c C-v s
#+kindex: C-c C-v C-s
#+kindex: C-c C-v d
#+kindex: C-c C-v C-d
#+kindex: C-c C-v t
#+kindex: C-c C-v C-t
#+kindex: C-c C-v f
#+kindex: C-c C-v C-f
#+kindex: C-c C-v c
#+kindex: C-c C-v C-c
#+kindex: C-c C-v j
#+kindex: C-c C-v C-j
#+kindex: C-c C-v l
#+kindex: C-c C-v C-l
#+kindex: C-c C-v i
#+kindex: C-c C-v C-i
#+kindex: C-c C-v I
#+kindex: C-c C-v C-I
#+kindex: C-c C-v z
#+kindex: C-c C-v C-z
#+kindex: C-c C-v a
#+kindex: C-c C-v C-a
#+kindex: C-c C-v h
#+kindex: C-c C-v C-h
#+kindex: C-c C-v x
#+kindex: C-c C-v C-x
#+findex: org-babel-previous-src-block
#+findex: org-babel-next-src-block
#+findex: org-babel-execute-maybe
#+findex: org-babel-open-src-block-result
#+findex: org-babel-expand-src-block
#+findex: org-babel-goto-src-block-head
#+findex: org-babel-goto-named-src-block
#+findex: org-babel-goto-named-result
#+findex: org-babel-execute-buffer
#+findex: org-babel-execute-subtree
#+findex: org-babel-demarcate-block
#+findex: org-babel-tangle
#+findex: org-babel-tangle-file
#+findex: org-babel-check-src-block
#+findex: org-babel-insert-header-arg
#+findex: org-babel-load-in-session
#+findex: org-babel-lob-ingest
#+findex: org-babel-view-src-block-info
#+findex: org-babel-switch-to-session-with-code
#+findex: org-babel-sha1-hash
#+findex: org-babel-describe-bindings
#+findex: org-babel-do-key-sequence-in-edit-buffer
#+attr_texinfo: :columns 0.45 0.55
| Key binding                                    | Function                                   |
|------------------------------------------------+--------------------------------------------|
| {{{kbd(C-c C-v p)}}} or {{{kbd(C-c C-v C-p)}}} | ~org-babel-previous-src-block~             |
| {{{kbd(C-c C-v n)}}} or {{{kbd(C-c C-v C-n)}}} | ~org-babel-next-src-block~                 |
| {{{kbd(C-c C-v e)}}} or {{{kbd(C-c C-v C-e)}}} | ~org-babel-execute-maybe~                  |
| {{{kbd(C-c C-v o)}}} or {{{kbd(C-c C-v C-o)}}} | ~org-babel-open-src-block-result~          |
| {{{kbd(C-c C-v v)}}} or {{{kbd(C-c C-v C-v)}}} | ~org-babel-expand-src-block~               |
| {{{kbd(C-c C-v u)}}} or {{{kbd(C-c C-v C-u)}}} | ~org-babel-goto-src-block-head~            |
| {{{kbd(C-c C-v g)}}} or {{{kbd(C-c C-v C-g)}}} | ~org-babel-goto-named-src-block~           |
| {{{kbd(C-c C-v r)}}} or {{{kbd(C-c C-v C-r)}}} | ~org-babel-goto-named-result~              |
| {{{kbd(C-c C-v b)}}} or {{{kbd(C-c C-v C-b)}}} | ~org-babel-execute-buffer~                 |
| {{{kbd(C-c C-v s)}}} or {{{kbd(C-c C-v C-s)}}} | ~org-babel-execute-subtree~                |
| {{{kbd(C-c C-v d)}}} or {{{kbd(C-c C-v C-d)}}} | ~org-babel-demarcate-block~                |
| {{{kbd(C-c C-v t)}}} or {{{kbd(C-c C-v C-t)}}} | ~org-babel-tangle~                         |
| {{{kbd(C-c C-v f)}}} or {{{kbd(C-c C-v C-f)}}} | ~org-babel-tangle-file~                    |
| {{{kbd(C-c C-v c)}}} or {{{kbd(C-c C-v C-c)}}} | ~org-babel-check-src-block~                |
| {{{kbd(C-c C-v j)}}} or {{{kbd(C-c C-v C-j)}}} | ~org-babel-insert-header-arg~              |
| {{{kbd(C-c C-v l)}}} or {{{kbd(C-c C-v C-l)}}} | ~org-babel-load-in-session~                |
| {{{kbd(C-c C-v i)}}} or {{{kbd(C-c C-v C-i)}}} | ~org-babel-lob-ingest~                     |
| {{{kbd(C-c C-v I)}}} or {{{kbd(C-c C-v C-I)}}} | ~org-babel-view-src-block-info~            |
| {{{kbd(C-c C-v z)}}} or {{{kbd(C-c C-v C-z)}}} | ~org-babel-switch-to-session-with-code~    |
| {{{kbd(C-c C-v a)}}} or {{{kbd(C-c C-v C-a)}}} | ~org-babel-sha1-hash~                      |
| {{{kbd(C-c C-v h)}}} or {{{kbd(C-c C-v C-h)}}} | ~org-babel-describe-bindings~              |
| {{{kbd(C-c C-v x)}}} or {{{kbd(C-c C-v C-x)}}} | ~org-babel-do-key-sequence-in-edit-buffer~ |

** Batch Execution
:PROPERTIES:
:DESCRIPTION: Call functions from the command line.
:END:
#+cindex: code block, batch execution
#+cindex: source code, batch execution

Org mode features, including working with source code facilities can
be invoked from the command line.  This enables building shell scripts
for batch processing, running automated system tasks, and expanding
Org mode's usefulness.

The sample script shows batch processing of multiple files using
~org-babel-tangle~.

#+begin_example
#!/bin/sh
# Tangle files with Org mode
#
emacs -Q --batch --eval "
    (progn
      (require 'ob-tangle)
      (dolist (file command-line-args-left)
        (with-current-buffer (find-file-noselect file)
          (org-babel-tangle))))
  " "$@"
#+end_example

* Miscellaneous
:PROPERTIES:
:DESCRIPTION: All the rest which did not fit elsewhere.
:END:

** Completion
:PROPERTIES:
:DESCRIPTION: @kbd{M-@key{TAB}} guesses completions.
:END:
#+cindex: completion, of @TeX{} symbols
#+cindex: completion, of TODO keywords
#+cindex: completion, of dictionary words
#+cindex: completion, of option keywords
#+cindex: completion, of tags
#+cindex: completion, of property keys
#+cindex: completion, of link abbreviations
#+cindex: @TeX{} symbol completion
#+cindex: TODO keywords completion
#+cindex: dictionary word completion
#+cindex: option keyword completion
#+cindex: tag completion
#+cindex: link abbreviations, completion of

Org has in-buffer completions.  Unlike minibuffer completions, which
are useful for quick command interactions, Org's in-buffer completions
are more suitable for content creation in Org documents.  Type one or
more letters and invoke the hot key to complete the text in-place.
Depending on the context and the keys, Org offers different types of
completions.  No minibuffer is involved.  Such mode-specific hot keys
have become an integral part of Emacs and Org provides several
shortcuts.

- {{{kbd(M-TAB)}}} ::
  #+kindex: M-TAB

  Complete word at point.

  - At the beginning of an empty headline, complete TODO keywords.

  - After =\=, complete TeX symbols supported by the exporter.

  - After =:= in a headline, complete tags.  Org deduces the list of
    tags from the =TAGS= in-buffer option (see [[*Setting Tags]]), the
    variable ~org-tag-alist~, or from all tags used in the current
    buffer.

  - After =:= and not in a headline, complete property keys.  The list
    of keys is constructed dynamically from all keys used in the
    current buffer.

  - After =[[=, complete link abbreviations (see [[*Link Abbreviations]]).

  - After =[[*=, complete headlines in the current buffer so that they
    can be used in search links like: =[[*find this headline]]=

  - After =#+=, complete the special keywords like =TYP_TODO= or
    file-specific =OPTIONS=.  After option keyword is complete,
    pressing {{{kbd(M-TAB)}}} again inserts example settings for this
    keyword.

  - After =STARTUP= keyword, complete startup items.

  - When point is anywhere else, complete dictionary words using
    Ispell.

** Structure Templates
:PROPERTIES:
:DESCRIPTION: Quick insertion of structural elements.
:END:
#+cindex: template insertion
#+cindex: insertion, of templates

With just a few keystrokes, it is possible to insert empty structural
blocks, such as =#+BEGIN_SRC= ... =#+END_SRC=, or to wrap existing
text in such a block.

- {{{kbd(C-c C-\,)}}} (~org-insert-structure-template~) ::

  #+findex: org-insert-structure-template
  #+kindex: C-c C-,
  Prompt for a type of block structure, and insert the block at point.
  If the region is active, it is wrapped in the block.  First prompts
  the user for keys, which are used to look up a structure type from
  the variable below.  If the key is {{{kbd(TAB)}}}, {{{kbd(RET)}}},
  or {{{kbd(SPC)}}}, the user is prompted to enter a block type.

#+vindex: org-structure-template-alist
Available structure types are defined in
~org-structure-template-alist~, see the docstring for adding or
changing values.

#+cindex: Tempo
#+cindex: template expansion
#+cindex: insertion, of templates
#+vindex: org-tempo-keywords-alist
Org Tempo expands snippets to structures defined in
~org-structure-template-alist~ and ~org-tempo-keywords-alist~.  For
example, {{{kbd(< s TAB)}}} creates a code block.  Enable it by
customizing ~org-modules~ or add =(require 'org-tempo)= to your Emacs
init file[fn:: For more information, please refer to the commentary
section in =org-tempo.el=.].

#+attr_texinfo: :columns 0.1 0.9
| {{{kbd(a)}}} | =#+BEGIN_EXPORT ascii= ... =#+END_EXPORT= |
| {{{kbd(c)}}} | =#+BEGIN_CENTER= ... =#+END_CENTER=       |
| {{{kbd(C)}}} | =#+BEGIN_COMMENT= ... =#+END_COMMENT=     |
| {{{kbd(e)}}} | =#+BEGIN_EXAMPLE= ... =#+END_EXAMPLE=     |
| {{{kbd(E)}}} | =#+BEGIN_EXPORT= ... =#+END_EXPORT=       |
| {{{kbd(h)}}} | =#+BEGIN_EXPORT html= ... =#+END_EXPORT=  |
| {{{kbd(l)}}} | =#+BEGIN_EXPORT latex= ... =#+END_EXPORT= |
| {{{kbd(q)}}} | =#+BEGIN_QUOTE= ... =#+END_QUOTE=         |
| {{{kbd(s)}}} | =#+BEGIN_SRC= ... =#+END_SRC=             |
| {{{kbd(v)}}} | =#+BEGIN_VERSE= ... =#+END_VERSE=         |

** Speed Keys
:PROPERTIES:
:DESCRIPTION: Electric commands at the beginning of a headline.
:END:
#+cindex: speed keys

Single keystrokes can execute custom commands in an Org file when
point is on a headline.  Without the extra burden of a meta or
modifier key, Speed Keys can speed navigation or execute custom
commands.  Besides faster navigation, Speed Keys may come in handy on
small mobile devices that do not have full keyboards.  Speed Keys may
also work on TTY devices known for their problems when entering Emacs
key chords.

#+vindex: org-use-speed-commands
By default, Org has Speed Keys disabled.  To activate Speed Keys, set
the variable ~org-use-speed-commands~ to a non-~nil~ value.  To
trigger a Speed Key, point must be at the beginning of an Org
headline, before any of the stars.

#+vindex: org-speed-commands
#+findex: org-speed-command-help
Org comes with a pre-defined list of Speed Keys.  To add or modify
Speed Keys, customize the option ~org-speed-commands~.  For more
details, see the variable's docstring.  With Speed Keys activated,
{{{kbd(M-x org-speed-command-help)}}}, or {{{kbd(?)}}} when point is at the
beginning of an Org headline, shows currently active Speed Keys,
including the user-defined ones.

** A Cleaner Outline View
:PROPERTIES:
:DESCRIPTION: Getting rid of leading stars in the outline.
:ALT_TITLE: Clean View
:END:
#+cindex: hiding leading stars
#+cindex: dynamic indentation
#+cindex: odd-levels-only outlines
#+cindex: clean outline view

Org's outline with stars and no indents can look cluttered for short
documents.  For /book-like/ long documents, the effect is not as
noticeable.  Org provides an alternate stars and indentation scheme,
as shown on the right in the following table.  It displays only one
star and indents text to line up with the heading:

#+begin_example
,* Top level headline             |    * Top level headline
,** Second level                  |      * Second level
,*** Third level                  |        * Third level
some text                        |          some text
,*** Third level                  |        * Third level
more text                        |          more text
,* Another top level headline     |    * Another top level headline
#+end_example

Org can achieve this in two ways, (1) by just displaying the buffer in
this way without changing it, or (2) by actually indenting every line
in the desired amount with hard spaces and hiding leading stars.

*** Org Indent Mode

#+cindex: Indent mode
#+findex: org-indent-mode
To display the buffer in the indented view, activate Org Indent minor
mode, using {{{kbd(M-x org-indent-mode)}}}.  Text lines that are not
headlines are prefixed with virtual spaces to vertically align with
the headline text[fn:49].

#+vindex: org-indent-indentation-per-level
To make more horizontal space, the headlines are shifted by two
characters.  Configure ~org-indent-indentation-per-level~ variable for
a different number.

#+vindex: org-indent-mode-turns-on-hiding-stars
#+vindex: org-indent-mode-turns-off-org-adapt-indentation
By default, Org Indent mode turns off ~org-adapt-indentation~ and does
hide leading stars by locally setting ~org-hide-leading-stars~ to ~t~:
only one star on each headline is visible, the rest are masked with
the same font color as the background.  If you want to customize this
default behavior, see ~org-indent-mode-turns-on-hiding-stars~ and
~org-indent-mode-turns-off-org-adapt-indentation~.

#+vindex: org-startup-indented
To globally turn on Org Indent mode for all files, customize the
variable ~org-startup-indented~.  To control it for individual files,
use =STARTUP= keyword as follows:

: #+STARTUP: indent
: #+STARTUP: noindent

*** Hard indentation

It is possible to use hard spaces to achieve the indentation instead,
if the bare ASCII file should have the indented look also outside
Emacs[fn:50].  With Org's support, you have to indent all lines to
line up with the outline headers.  You would use these settings[fn::
~org-adapt-indentation~ can also be set to ='headline-data=, in which
case only data lines below the headline will be indented.]:

#+begin_src emacs-lisp
(setq org-adapt-indentation t
      org-hide-leading-stars t
      org-odd-levels-only t)
#+end_src

- /Indentation of text below headlines/ (~org-adapt-indentation~) ::

  #+vindex: org-adapt-indentation
  The first setting modifies paragraph filling, line wrapping, and
  structure editing commands to preserving or adapting the indentation
  as appropriate.

- /Hiding leading stars/ (~org-hide-leading-stars~) ::

  #+vindex: org-hide-leading-stars
  #+vindex: org-hide, face
  The second setting makes leading stars invisible by applying the
  face ~org-hide~ to them.  For per-file preference, use these file
  =STARTUP= options:

  #+begin_example
  ,#+STARTUP: hidestars
  ,#+STARTUP: showstars
  #+end_example

- /Odd levels/ (~org-odd-levels-only~) ::

  #+vindex: org-odd-levels-only
  The third setting makes Org use only odd levels, 1, 3, 5, ..., in
  the outline to create more indentation.  On a per-file level,
  control this with:

  #+begin_example
  ,#+STARTUP: odd
  ,#+STARTUP: oddeven
  #+end_example

  To convert a file between single and double stars layouts, use
  {{{kbd(M-x org-convert-to-odd-levels)}}} and {{{kbd(M-x
  org-convert-to-oddeven-levels)}}}.

** Execute commands in the active region
:PROPERTIES:
:DESCRIPTION: Execute commands on multiple items in Org or agenda view.
:END:

#+vindex: org-loop-over-headlines-in-active-region
When in an Org buffer and the region is active, some commands will
apply to all the subtrees in the active region.  For example, hitting
{{{kbd(C-c C-s)}}} when multiple headlines are within the active region will
successively prompt you for a new schedule date and time.  To disable
this, set the option ~org-loop-over-headlines-in-active-region~ to
non-~t~, activate the region and run the command normally.

#+vindex: org-agenda-loop-over-headlines-in-active-region
~org-agenda-loop-over-headlines-in-active-region~ is the equivalent
option of the agenda buffer, where you can also use [[*Bulk remote editing selected entries][bulk editing of
selected entries]].

Not all commands can loop in the active region and what subtrees or
headlines are considered can be refined: see the docstrings of these
options for more details.

** Dynamic Headline Numbering
:PROPERTIES:
:DESCRIPTION: Display and update outline numbering.
:END:

#+cindex: Org Num mode
#+cindex: number headlines
The Org Num minor mode, toggled with {{{kbd(M-x org-num-mode)}}},
displays outline numbering on top of headlines.  It also updates it
automatically upon changes to the structure of the document.

#+vindex: org-num-max-level
#+vindex: org-num-skip-tags
#+vindex: org-num-skip-commented
#+vindex: org-num-skip-unnumbered
By default, all headlines are numbered.  You can limit numbering to
specific headlines according to their level, tags, =COMMENT= keyword,
or =UNNUMBERED= property.  Set ~org-num-max-level~,
~org-num-skip-tags~, ~org-num-skip-commented~,
~org-num-skip-unnumbered~, or ~org-num-skip-footnotes~ accordingly.

#+vindex: org-num-skip-footnotes
If ~org-num-skip-footnotes~ is non-~nil~, footnotes sections (see
[[*Creating Footnotes]]) are not numbered either.

#+vindex: org-num-face
#+vindex: org-num-format-function
You can control how the numbering is displayed by setting
~org-num-face~ and ~org-num-format-function~.

#+vindex: org-startup-numerated
You can also turn this mode globally for all Org files by setting the
option ~org-startup-numerated~ to =t=, or locally on a file by using
=#+startup: num=.

** The Very Busy {{{kbd(C-c C-c)}}} Key
:PROPERTIES:
:DESCRIPTION: When in doubt, press @kbd{C-c C-c}.
:END:
#+kindex: C-c C-c
#+cindex: @kbd{C-c C-c}, overview

The {{{kbd(C-c C-c)}}} key in Org serves many purposes depending on
the context.  It is probably the most over-worked, multi-purpose key
combination in Org.  Its uses are well documented throughout this
manual, but here is a consolidated list for easy reference.

- If column view (see [[*Column View]]) is on, exit column view.

- If any highlights shown in the buffer from the creation of a sparse
  tree, or from clock display, remove such highlights.

- If point is in one of the special =KEYWORD= lines, scan the buffer
  for these lines and update the information.  Also reset the Org file
  cache used to temporary store the contents of URLs used as values
  for keywords like =SETUPFILE=.

- If point is inside a table, realign the table.

- If point is on a =TBLFM= keyword, re-apply the formulas to the
  entire table.

- If the current buffer is a capture buffer, close the note and file
  it.  With a prefix argument, also jump to the target location after
  saving the note.

- If point is on a =<<<target>>>=, update radio targets and
  corresponding links in this buffer.

- If point is on a property line or at the start or end of a property
  drawer, offer property commands.

- If point is at a footnote reference, go to the corresponding
  definition, and /vice versa/.

- If point is on a statistics cookie, update it.

- If point is in a plain list item with a checkbox, toggle the status
  of the checkbox.

- If point is on a numbered item in a plain list, renumber the ordered
  list.

- If point is on the =#+BEGIN= line of a dynamic block, the block is
  updated.

- If point is at a timestamp, fix the day name in the timestamp.

** Summary of In-Buffer Settings
:PROPERTIES:
:DESCRIPTION: Overview of keywords.
:ALT_TITLE: In-buffer Settings
:END:
#+cindex: in-buffer settings
#+cindex: special keywords

In-buffer settings start with =#+=, followed by a keyword, a colon,
one or more spaces, and then a word for each setting.  Org accepts
multiple settings on the same line.  Org also accepts multiple lines
for a keyword.  This manual describes these settings throughout.  A
summary follows here.

#+cindex: refresh set-up
{{{kbd(C-c C-c)}}} activates any changes to the in-buffer settings.
Closing and reopening the Org file in Emacs also activates the
changes.

#+attr_texinfo: :sep ,
- =#+ARCHIVE: %s_done::= ::

  #+cindex: @samp{ARCHIVE}, keyword
  #+vindex: org-archive-location
  Sets the archive location of the agenda file.  The corresponding
  variable is ~org-archive-location~.

- =#+CATEGORY= ::

  #+cindex: @samp{CATEGORY}, keyword
  Sets the category of the agenda file, which applies to the entire
  document.

- =#+COLUMNS: %25ITEM ...= ::

  #+cindex: @samp{COLUMNS}, property
  Set the default format for columns view.  This format applies when
  columns view is invoked in locations where no =COLUMNS= property
  applies.

- =#+CONSTANTS: name1=value1 ...= ::

  #+cindex: @samp{CONSTANTS}, keyword
  #+vindex: org-table-formula-constants
  #+vindex: org-table-formula
  Set file-local values for constants that table formulas can use.
  This line sets the local variable
  ~org-table-formula-constants-local~.  The global version of this
  variable is ~org-table-formula-constants~.

- =#+FILETAGS: :tag1:tag2:tag3:= ::

  #+cindex: @samp{FILETAGS}, keyword
  Set tags that all entries in the file inherit from, including the
  top-level entries.

- =#+LINK: linkword replace= ::

  #+cindex: @samp{LINK}, keyword
  #+vindex: org-link-abbrev-alist
  Each line specifies one abbreviation for one link.  Use multiple
  =LINK= keywords for more, see [[*Link Abbreviations]].  The
  corresponding variable is ~org-link-abbrev-alist~.

- =#+PRIORITIES: highest lowest default= ::

  #+cindex: @samp{PRIORITIES}, keyword
  #+vindex: org-priority-highest
  #+vindex: org-priority-lowest
  #+vindex: org-priority-default
  This line sets the limits and the default for the priorities.  All
  three must be either letters A--Z or numbers 0--9.  The highest
  priority must have a lower ASCII number than the lowest priority.

- =#+PROPERTY: Property_Name Value= ::

  #+cindex: @samp{PROPERTY}, keyword
  This line sets a default inheritance value for entries in the
  current buffer, most useful for specifying the allowed values of
  a property.

- =#+SETUPFILE: file= ::

  #+cindex: @samp{SETUPFILE}, keyword
  The setup file or a URL pointing to such file is for additional
  in-buffer settings.  Org loads this file and parses it for any
  settings in it only when Org opens the main file.  If URL is
  specified, the contents are downloaded and stored in a temporary
  file cache.  {{{kbd(C-c C-c)}}} on the settings line parses and
  loads the file, and also resets the temporary file cache.  Org also
  parses and loads the document during normal exporting process.  Org
  parses the contents of this document as if it was included in the
  buffer.  It can be another Org file.  To visit the file---not
  a URL---use {{{kbd(C-c ')}}} while point is on the line with the
  file name.

- =#+STARTUP:= ::

  #+cindex: @samp{STARTUP}, keyword
  Startup options Org uses when first visiting a file.

  #+vindex: org-startup-folded
  The first set of options deals with the initial visibility of the
  outline tree.  The corresponding variable for global default
  settings is ~org-startup-folded~ with a default value of
  ~showeverything~.

  | =overview=       | Top-level headlines only.  |
  | =content=        | All headlines.             |
  | =showall=        | No folding on any entry.   |
  | =show2levels=    | Headline levels 1-2.       |
  | =show3levels=    | Headline levels 1-3.       |
  | =show4levels=    | Headline levels 1-4.       |
  | =show5levels=    | Headline levels 1-5.       |
  | =showeverything= | Show even drawer contents. |

  #+vindex: org-startup-indented
  Dynamic virtual indentation is controlled by the variable
  ~org-startup-indented~[fn:: Note that Org Indent mode also sets the
  ~wrap-prefix~ property, such that Visual Line mode (or purely
  setting ~word-wrap~) wraps long lines, including headlines,
  correctly indented.].

  | =indent=   | Start with Org Indent mode turned on.  |
  | =noindent= | Start with Org Indent mode turned off. |

  #+vindex: org-startup-numerated
  Dynamic virtual numeration of headlines is controlled by the variable
  ~org-startup-numerated~.

  | =num=   | Start with Org num mode turned on.  |
  | =nonum= | Start with Org num mode turned off. |

  #+vindex: org-startup-align-all-tables
  Aligns tables consistently upon visiting a file.  The
  corresponding variable is ~org-startup-align-all-tables~ with
  ~nil~ as default value.

  | =align=   | Align all tables.               |
  | =noalign= | Do not align tables on startup. |

  #+vindex: org-startup-shrink-all-tables
  Shrink table columns with a width cookie.  The corresponding
  variable is ~org-startup-shrink-all-tables~ with ~nil~ as
  default value.

  #+vindex: org-startup-with-inline-images
  When visiting a file, inline images can be automatically
  displayed.  The corresponding variable is
  ~org-startup-with-inline-images~, with a default value ~nil~ to
  avoid delays when visiting a file.

  | =inlineimages=   | Show inline images.                   |
  | =noinlineimages= | Do not show inline images on startup. |

  #+vindex: org-log-done
  #+vindex: org-log-note-clock-out
  #+vindex: org-log-repeat
  Logging the closing and reopening of TODO items and clock
  intervals can be configured using these options (see variables
  ~org-log-done~, ~org-log-note-clock-out~, and ~org-log-repeat~).

  | =logdone=            | Record a timestamp when an item is marked as done. |
  | =lognotedone=        | Record timestamp and a note when DONE.             |
  | =nologdone=          | Do not record when items are marked as done.       |
  | =logrepeat=          | Record a time when reinstating a repeating item.   |
  | =lognoterepeat=      | Record a note when reinstating a repeating item.   |
  | =nologrepeat=        | Do not record when reinstating repeating item.     |
  | =lognoteclock-out=   | Record a note when clocking out.                   |
  | =nolognoteclock-out= | Do not record a note when clocking out.            |
  | =logreschedule=      | Record a timestamp when scheduling time changes.   |
  | =lognotereschedule=  | Record a note when scheduling time changes.        |
  | =nologreschedule=    | Do not record when a scheduling date changes.      |
  | =logredeadline=      | Record a timestamp when deadline changes.          |
  | =lognoteredeadline=  | Record a note when deadline changes.               |
  | =nologredeadline=    | Do not record when a deadline date changes.        |
  | =logrefile=          | Record a timestamp when refiling.                  |
  | =lognoterefile=      | Record a note when refiling.                       |
  | =nologrefile=        | Do not record when refiling.                       |

  #+vindex: org-hide-leading-stars
  #+vindex: org-odd-levels-only
  Here are the options for hiding leading stars in outline
  headings, and for indenting outlines.  The corresponding
  variables are ~org-hide-leading-stars~ and
  ~org-odd-levels-only~, both with a default setting ~nil~
  (meaning =showstars= and =oddeven=).

  | =hidestars= | Make all but one of the stars starting a headline invisible. |
  | =showstars= | Show all stars starting a headline.                          |
  | =indent=    | Virtual indentation according to outline level.              |
  | =noindent=  | No virtual indentation according to outline level.           |
  | =odd=       | Allow only odd outline levels (1, 3, ...).                   |
  | =oddeven=   | Allow all outline levels.                                    |

  #+vindex: org-put-time-stamp-overlays
  #+vindex: org-time-stamp-overlay-formats
  To turn on custom format overlays over timestamps (variables
  ~org-put-time-stamp-overlays~ and
  ~org-time-stamp-overlay-formats~), use:

  | =customtime= | Overlay custom time format. |

  #+vindex: constants-unit-system
  The following options influence the table spreadsheet (variable
  ~constants-unit-system~).

  | =constcgs= | =constants.el= should use the c-g-s unit system. |
  | =constSI=  | =constants.el= should use the SI unit system.    |

  #+vindex: org-footnote-define-inline
  #+vindex: org-footnote-auto-label
  #+vindex: org-footnote-auto-adjust
  To influence footnote settings, use the following keywords.  The
  corresponding variables are ~org-footnote-define-inline~,
  ~org-footnote-auto-label~, and ~org-footnote-auto-adjust~.

  | =fninline=   | Define footnotes inline.                               |
  | =fnnoinline= | Define footnotes in separate section.                  |
  | =fnlocal=    | Define footnotes near first reference, but not inline. |
  | =fnprompt=   | Prompt for footnote labels.                            |
  | =fnauto=     | Create =[fn:1]=-like labels automatically (default).   |
  | =fnconfirm=  | Offer automatic label for editing or confirmation.     |
  | =fnadjust=   | Automatically renumber and sort footnotes.             |
  | =nofnadjust= | Do not renumber and sort automatically.                |

  #+vindex: org-hide-block-startup
  #+vindex: org-hide-drawer-startup
  To hide blocks or drawers on startup, use these keywords.  The
  corresponding variables are ~org-hide-block-startup~ and
  ~org-hide-drawer-startup~.

  | =hideblocks=    | Hide all begin/end blocks on startup. |
  | =nohideblocks=  | Do not hide blocks on startup.        |
  | =hidedrawers=   | Hide all begin/end blocks on startup. |
  | =nohidedrawers= | Do not hide blocks on startup.        |


  #+vindex: org-pretty-entities
  The display of entities as UTF-8 characters is governed by the
  variable ~org-pretty-entities~ and the keywords

  | =entitiespretty= | Show entities as UTF-8 characters where possible. |
  | =entitiesplain=  | Leave entities plain.                             |

- =#+TAGS: TAG1(c1) TAG2(c2)= ::

  #+cindex: @samp{TAGS}, keyword
  #+vindex: org-tag-alist
  These lines (several such lines are allowed) specify the valid tags
  in this file, and (potentially) the corresponding /fast tag
  selection/ keys.  The corresponding variable is ~org-tag-alist~.

- =#+TODO:=, =#+SEQ_TODO:=, =#+TYP_TODO:= ::

  #+cindex: @samp{SEQ_TODO}, keyword
  #+cindex: @samp{TODO}, keyword
  #+cindex: @samp{TYP_TODO}, keyword
  #+vindex: org-todo-keywords
  These lines set the TODO keywords and their interpretation in the
  current file.  The corresponding variable is ~org-todo-keywords~.

** Regular Expressions
:PROPERTIES:
:DESCRIPTION: Elisp regular expressions.
:END:
#+cindex: regular expressions syntax
#+cindex: regular expressions, in searches

Org, as an Emacs mode, makes use of Elisp regular expressions for
searching, matching and filtering.  Elisp regular expressions have a
somewhat different syntax then some common standards.  Most notably,
alternation is indicated using =\|= and matching groups are denoted by
=\(...\)=.  For example the string =home\|work= matches either =home=
or =work=.

For more information, see [[info:emacs::Regexps][Regular Expressions in Emacs]].

** Org Syntax
:PROPERTIES:
:DESCRIPTION: Formal description of Org's syntax.
:END:

A reference document providing a formal description of Org's syntax is
available as [[https://orgmode.org/worg/dev/org-syntax.html][a draft on Worg]], written and maintained by Nicolas
Goaziou.  It defines Org's core internal concepts such as "headlines",
"sections", "affiliated keywords", "(greater) elements" and "objects".
Each part of an Org document belongs to one of the previous
categories.

To explore the abstract structure of an Org buffer, run this in
a buffer:

: M-: (org-element-parse-buffer) <RET>

#+texinfo: @noindent
It outputs a list containing the buffer's content represented as an
abstract structure.  The export engine relies on the information
stored in this list.  Most interactive commands---e.g., for structure
editing---also rely on the syntactic meaning of the surrounding
context.

#+cindex: syntax checker
#+cindex: linter
#+findex: org-lint
You can probe the syntax of your documents with the command

: M-x org-lint <RET>

#+texinfo: @noindent
It runs a number of checks to find common mistakes.  It then displays
their location in a dedicated buffer, along with a description and
a "trust level", since false-positive are possible.  From there, you
can operate on the reports with the following keys:

#+attr_texinfo: :columns 0.22 0.78
| {{{kbd(C-j)}}}, {{{kbd(TAB)}}} | Display the offending line                  |
| {{{kbd(RET)}}}                 | Move point to the offending line            |
| {{{kbd(g)}}}                   | Check the document again                    |
| {{{kbd(h)}}}                   | Hide all reports from the same checker      |
| {{{kbd(i)}}}                   | Also remove them from all subsequent checks |
| {{{kbd(S)}}}                   | Sort reports by the column at point         |

** Context Dependent Documentation
:PROPERTIES:
:DESCRIPTION: Read documentation about current syntax.
:ALT_TITLE: Documentation Access
:END:
#+cindex: documentation
#+cindex: Info

#+findex: org-info-find-node
#+kindex: C-c C-x I
{{{kbd(C-c C-x I)}}} in an Org file tries to open a suitable section
of the Org manual depending on the syntax at point.  For example,
using it on a headline displays "Document Structure" section.

{{{kbd(q)}}} closes the Info window.

** Escape Character
:PROPERTIES:
:DESCRIPTION: Prevent Org from interpreting your writing.
:END:

#+cindex: escape character
#+cindex: zero width space
You may sometimes want to write text that looks like Org syntax, but
should really read as plain text.  Org may use a specific escape
character in some situations, i.e., a backslash in macros (see [[*Macro
Replacement]]) and links (see [[*Link Format]]), or a comma in source and
example blocks (see [[*Literal Examples]]).  In the general case, however,
we suggest to use the zero width space.  You can insert one with any
of the following:

: C-x 8 <RET> zero width space <RET>
: C-x 8 <RET> 200B <RET>

For example, in order to write =[[1,2]]= as-is in your document, you
may write instead

: [X[1,2]]

where =X= denotes the zero width space character.

** Code Evaluation and Security Issues
:PROPERTIES:
:DESCRIPTION: Org files evaluate in-line code.
:ALT_TITLE: Code Evaluation Security
:END:

Unlike plain text, running code comes with risk.  Each source code
block, in terms of risk, is equivalent to an executable file.  Org
therefore puts a few confirmation prompts by default.  This is to
alert the casual user from accidentally running untrusted code.

For users who do not run code blocks or write code regularly, Org's
default settings should suffice.  However, some users may want to
tweak the prompts for fewer interruptions.  To weigh the risks of
automatic execution of code blocks, here are some details about code
evaluation.

Org evaluates code in the following circumstances:

- /Source code blocks/ ::

  Org evaluates source code blocks in an Org file during export.  Org
  also evaluates a source code block with the {{{kbd(C-c C-c)}}} key
  chord.  Users exporting or running code blocks must load files only
  from trusted sources.  Be wary of customizing variables that remove
  or alter default security measures.

  #+attr_texinfo: :options org-confirm-babel-evaluate
  #+begin_defopt
  When ~t~, Org prompts the user for confirmation before executing
  each code block.  When ~nil~, Org executes code blocks without
  prompting the user for confirmation.  When this option is set to
  a custom function, Org invokes the function with these two
  arguments: the source code language and the body of the code block.
  The custom function must return either a ~t~ or ~nil~, which
  determines if the user is prompted.  Each source code language can
  be handled separately through this function argument.
  #+end_defopt

  For example, here is how to execute ditaa code blocks without
  prompting:

  #+begin_src emacs-lisp
  (defun my-org-confirm-babel-evaluate (lang body)
    (not (string= lang "ditaa")))  ;don't ask for ditaa
  (setq org-confirm-babel-evaluate #'my-org-confirm-babel-evaluate)
  #+end_src

- /Following =shell= and =elisp= links/ ::

  Org has two link types that can directly evaluate code (see
  [[*External Links]]).  Because such code is not visible, these links
  have a potential risk.  Org therefore prompts the user when it
  encounters such links.  The customization variables are:

  #+attr_texinfo: :options org-link-shell-confirm-function
  #+begin_defopt
  Function that prompts the user before executing a shell link.
  #+end_defopt

  #+attr_texinfo: :options org-link-elisp-confirm-function
  #+begin_defopt
  Function that prompts the user before executing an Emacs Lisp link.
  #+end_defopt

- /Formulas in tables/ ::

  Formulas in tables (see [[*The Spreadsheet]]) are code that is evaluated
  either by the Calc interpreter, or by the Emacs Lisp interpreter.

** Interaction with Other Packages
:PROPERTIES:
:DESCRIPTION: With other Emacs packages.
:ALT_TITLE: Interaction
:END:
#+cindex: packages, interaction with other

Org's compatibility and the level of interaction with other Emacs
packages are documented here.

*** Packages that Org cooperates with
:PROPERTIES:
:DESCRIPTION: Packages Org cooperates with.
:ALT_TITLE: Cooperation
:END:

- =calc.el= by Dave Gillespie ::
  #+cindex: @file{calc.el}

  Org uses the Calc package for implementing spreadsheet functionality
  in its tables (see [[*The Spreadsheet]]).  Org also uses Calc for
  embedded calculations.  See [[info:calc::Embedded Mode][GNU Emacs Calc Manual]].

- =constants.el= by Carsten Dominik ::
  #+cindex: @file{constants.el}
  #+vindex: org-table-formula-constants

  Org can use names for constants in formulas in tables.  Org can also
  use calculation suffixes for units, such as =M= for =Mega=.  For
  a standard collection of such constants, install the =constants=
  package.  Install version 2.0 of this package, available at
  [[http://www.astro.uva.nl/~dominik/Tools]].  Org checks if the function
  ~constants-get~ has been autoloaded.  Installation instructions are
  in the file =constants.el=.

- =cdlatex.el= by Carsten Dominik ::
  #+cindex: @file{cdlatex.el}

  Org mode can make use of the CDLaTeX package to efficiently enter
  LaTeX fragments into Org files.  See [[*Using CDLaTeX to enter math]].

- =imenu.el= by Ake Stenhoff and Lars Lindberg ::
  #+cindex: @file{imenu.el}

  Imenu creates dynamic menus based on an index of items in a file.
  Org mode supports Imenu menus.  Enable it with a mode hook as
  follows:

  #+begin_src emacs-lisp
  (add-hook 'org-mode-hook
            (lambda () (imenu-add-to-menubar "Imenu")))
  #+end_src

  #+vindex: org-imenu-depth
  By default the index is two levels deep---you can modify the
  depth using the option ~org-imenu-depth~.

- =speedbar.el= by Eric\nbsp{}M.\nbsp{}Ludlam ::
  #+cindex: @file{speedbar.el}

  Speedbar package creates a special Emacs frame for displaying files
  and index items in files.  Org mode supports Speedbar; users can
  drill into Org files directly from the Speedbar.  The {{{kbd(<)}}}
  in the Speedbar frame tweaks the agenda commands to that file or to
  a subtree.

- =table.el= by Takaaki Ota ::
  #+cindex: table editor, @file{table.el}
  #+cindex: @file{table.el}

  Complex ASCII tables with automatic line wrapping, column- and
  row-spanning, and alignment can be created using the Emacs table
  package by Takaaki Ota.  Org mode recognizes such tables and exports
  them properly.  {{{kbd(C-c ')}}} to edit these tables in a special
  buffer, much like Org's code blocks.  Because of interference with
  other Org mode functionality, Takaaki Ota tables cannot be edited
  directly in the Org buffer.

  - {{{kbd(C-c ')}}} (~org-edit-special~) ::

    #+kindex: C-c '
    #+findex: org-edit-special
    Edit a =table.el= table.  Works when point is in a =table.el=
    table.

  - {{{kbd(C-c ~​)}}} (~org-table-create-with-table.el~) ::

    #+kindex: C-c ~
    #+findex: org-table-create-with-table.el
    Insert a =table.el= table.  If there is already a table at point,
    this command converts it between the =table.el= format and the Org
    mode format.  See the documentation string of the command
    ~org-convert-table~ for the restrictions under which this is
    possible.

*** Packages that conflict with Org mode
:PROPERTIES:
:DESCRIPTION: Packages that lead to conflicts.
:ALT_TITLE: Conflicts
:END:

#+cindex: shift-selection
#+vindex: org-support-shift-select
In Emacs, shift-selection combines motions of point with shift key to
enlarge regions.  Emacs sets this mode by default.  This conflicts
with Org's use of {{{kbd(S-<cursor>)}}} commands to change timestamps,
TODO keywords, priorities, and item bullet types, etc.  Since
{{{kbd(S-<cursor>)}}} commands outside of specific contexts do not do
anything, Org offers the variable ~org-support-shift-select~ for
customization.  Org mode accommodates shift selection by (i) making it
available outside of the special contexts where special commands
apply, and (ii) extending an existing active region even if point
moves across a special context.

- =cua.el= by Kim\nbsp{}F.\nbsp{}Storm ::

  #+cindex: @file{cua.el}
  #+vindex: org-replace-disputed-keys
  Org key bindings conflict with {{{kbd(S-<cursor>)}}} keys used by
  CUA mode.  For Org to relinquish these bindings to CUA mode,
  configure the variable ~org-replace-disputed-keys~.  When set, Org
  moves the following key bindings in Org files, and in the agenda
  buffer---but not during date selection.

  #+attr_texinfo: :columns 0.4 0.4
  | {{{kbd(S-UP)}}}      \rArr{}  {{{kbd(M-p)}}}   | {{{kbd(S-DOWN)}}}     \rArr{}  {{{kbd(M-n)}}}   |
  | {{{kbd(S-LEFT)}}}    \rArr{}  {{{kbd(M--)}}}   | {{{kbd(S-RIGHT)}}}    \rArr{}  {{{kbd(M-+)}}}   |
  | {{{kbd(C-S-LEFT)}}}  \rArr{}  {{{kbd(M-S--)}}} | {{{kbd(C-S-RIGHT)}}}  \rArr{}  {{{kbd(M-S-+)}}} |

  #+vindex: org-disputed-keys
  Yes, these are unfortunately more difficult to remember.  If you
  want to have other replacement keys, look at the variable
  ~org-disputed-keys~.

- =ecomplete.el= by Lars Magne Ingebrigtsen ::

  #+cindex: @file{ecomplete.el}
  Ecomplete provides "electric" address completion in address header
  lines in message buffers.  Sadly Orgtbl mode cuts Ecomplete's power
  supply: no completion happens when Orgtbl mode is enabled in message
  buffers while entering text in address header lines.  If one wants
  to use ecomplete one should /not/ follow the advice to automagically
  turn on Orgtbl mode in message buffers (see [[*The Orgtbl Minor Mode]]),
  but instead---after filling in the message headers---turn on Orgtbl
  mode manually when needed in the messages body.

- =filladapt.el= by Kyle Jones ::

  #+cindex: @file{filladapt.el}
  Org mode tries to do the right thing when filling paragraphs, list
  items and other elements.  Many users reported problems using both
  =filladapt.el= and Org mode, so a safe thing to do is to disable
  filladapt like this:

  #+begin_src emacs-lisp
  (add-hook 'org-mode-hook 'turn-off-filladapt-mode)
  #+end_src

- =viper.el= by Michael Kifer ::
  #+cindex: @file{viper.el}
  #+kindex: C-c /

  Viper uses {{{kbd(C-c /)}}} and therefore makes this key not access
  the corresponding Org mode command ~org-sparse-tree~.  You need to
  find another key for this command, or override the key in
  ~viper-vi-global-user-map~ with

  #+begin_src emacs-lisp
  (define-key viper-vi-global-user-map "C-c /" 'org-sparse-tree)
  #+end_src

- =windmove.el= by Hovav Shacham ::
  #+cindex: @file{windmove.el}

  This package also uses the {{{kbd(S-<cursor>)}}} keys, so everything
  written in the paragraph above about CUA mode also applies here.  If
  you want to make the windmove function active in locations where Org
  mode does not have special functionality on {{{kbd(S-<cursor>)}}},
  add this to your configuration:

  #+begin_src emacs-lisp
  ;; Make windmove work in Org mode:
  (add-hook 'org-shiftup-final-hook 'windmove-up)
  (add-hook 'org-shiftleft-final-hook 'windmove-left)
  (add-hook 'org-shiftdown-final-hook 'windmove-down)
  (add-hook 'org-shiftright-final-hook 'windmove-right)
  #+end_src

- =yasnippet.el= ::

  #+cindex: @file{yasnippet.el}
  The way Org mode binds the {{{kbd(TAB)}}} key (binding to ~[tab]~
  instead of ~"\t"~) overrules YASnippet's access to this key.  The
  following code fixed this problem:

  #+begin_src emacs-lisp
  (add-hook 'org-mode-hook
            (lambda ()
              (setq-local yas/trigger-key [tab])
              (define-key yas/keymap [tab] 'yas/next-field-or-maybe-expand)))
  #+end_src

  The latest version of YASnippet does not play well with Org mode.
  If the above code does not fix the conflict, start by defining
  the following function:

  #+begin_src emacs-lisp
  (defun yas/org-very-safe-expand ()
    (let ((yas/fallback-behavior 'return-nil)) (yas/expand)))
  #+end_src

  Then, tell Org mode to use that function:

  #+begin_src emacs-lisp
  (add-hook 'org-mode-hook
            (lambda ()
              (make-variable-buffer-local 'yas/trigger-key)
              (setq yas/trigger-key [tab])
              (add-to-list 'org-tab-first-hook 'yas/org-very-safe-expand)
              (define-key yas/keymap [tab] 'yas/next-field)))
  #+end_src

** Using Org on a TTY
:PROPERTIES:
:DESCRIPTION: Using Org on a tty.
:ALT_TITLE: TTY Keys
:END:
#+cindex: tty key bindings

Org provides alternative key bindings for TTY and modern mobile
devices that cannot perform movement commands on point and key
bindings with modifier keys.  Some of these workarounds may be more
cumbersome than necessary.  Users should look into customizing these
further based on their usage needs.  For example, the normal
{{{kbd(S-<cursor>)}}} for editing timestamp might be better with
{{{kbd(C-c .)}}} chord.

#+attr_texinfo: :columns 0.2 0.28 0.15 0.21
| Default              | Alternative 1            | Speed key    | Alternative 2        |
|----------------------+--------------------------+--------------+----------------------|
| {{{kbd(S-TAB)}}}     | {{{kbd(C-u TAB)}}}       | {{{kbd(C)}}} |                      |
| {{{kbd(M-LEFT)}}}    | {{{kbd(C-c C-x l)}}}     | {{{kbd(l)}}} | {{{kbd(Esc LEFT)}}}  |
| {{{kbd(M-S-LEFT)}}}  | {{{kbd(C-c C-x L)}}}     | {{{kbd(L)}}} |                      |
| {{{kbd(M-RIGHT)}}}   | {{{kbd(C-c C-x r)}}}     | {{{kbd(r)}}} | {{{kbd(Esc RIGHT)}}} |
| {{{kbd(M-S-RIGHT)}}} | {{{kbd(C-c C-x R)}}}     | {{{kbd(R)}}} |                      |
| {{{kbd(M-UP)}}}      | {{{kbd(C-c C-x u)}}}     |              | {{{kbd(Esc UP)}}}    |
| {{{kbd(M-S-UP)}}}    | {{{kbd(C-c C-x U)}}}     | {{{kbd(U)}}} |                      |
| {{{kbd(M-DOWN)}}}    | {{{kbd(C-c C-x d)}}}     |              | {{{kbd(Esc DOWN)}}}  |
| {{{kbd(M-S-DOWN)}}}  | {{{kbd(C-c C-x D)}}}     | {{{kbd(D)}}} |                      |
| {{{kbd(S-RET)}}}     | {{{kbd(C-c C-x c)}}}     |              |                      |
| {{{kbd(M-RET)}}}     | {{{kbd(C-c C-x m)}}}     |              | {{{kbd(Esc RET)}}}   |
| {{{kbd(M-S-RET)}}}   | {{{kbd(C-c C-x M)}}}     |              |                      |
| {{{kbd(S-LEFT)}}}    | {{{kbd(C-c LEFT)}}}      |              |                      |
| {{{kbd(S-RIGHT)}}}   | {{{kbd(C-c RIGHT)}}}     |              |                      |
| {{{kbd(S-UP)}}}      | {{{kbd(C-c UP)}}}        |              |                      |
| {{{kbd(S-DOWN)}}}    | {{{kbd(C-c DOWN)}}}      |              |                      |
| {{{kbd(C-S-LEFT)}}}  | {{{kbd(C-c C-x LEFT)}}}  |              |                      |
| {{{kbd(C-S-RIGHT)}}} | {{{kbd(C-c C-x RIGHT)}}} |              |                      |

** Protocols for External Access
:PROPERTIES:
:DESCRIPTION: External access to Emacs and Org.
:ALT_TITLE: Protocols
:END:
#+cindex: protocols, for external access

Org protocol is a tool to trigger custom actions in Emacs from
external applications.  Any application that supports calling external
programs with an URL as argument may be used with this functionality.
For example, you can configure bookmarks in your web browser to send a
link to the current page to Org and create a note from it using
capture (see [[*Capture]]).  You can also create a bookmark that tells
Emacs to open the local source file of a remote website you are
browsing.

#+cindex: Org protocol, set-up
#+cindex: Installing Org protocol
In order to use Org protocol from an application, you need to register
=org-protocol://= as a valid scheme-handler.  External calls are
passed to Emacs through the =emacsclient= command, so you also need to
ensure an Emacs server is running.  More precisely, when the
application calls

: emacsclient "org-protocol://PROTOCOL?key1=val1&key2=val2"

#+texinfo: @noindent
Emacs calls the handler associated to {{{var(PROTOCOL)}}} with
argument =(:key1 val1 :key2 val2)=.

#+cindex: protocol, new protocol
#+cindex: defining new protocols
Org protocol comes with three predefined protocols, detailed in the
following sections.  Configure ~org-protocol-protocol-alist~ to define
your own.

*** The ~store-link~ protocol
:PROPERTIES:
:DESCRIPTION: Store a link, push URL to kill-ring.
:END:
#+cindex: store-link protocol
#+cindex: protocol, store-link

Using the ~store-link~ handler, you can copy links, to that they can
be inserted using {{{kbd(M-x org-insert-link)}}} or yanking.  More
precisely, the command

: emacsclient "org-protocol://store-link?url=URL&title=TITLE"

#+texinfo: @noindent
stores the following link:

: [[URL][TITLE]]

In addition, {{{var(URL)}}} is pushed on the kill-ring for yanking.
You need to encode {{{var(URL)}}} and {{{var(TITLE)}}} if they contain
slashes, and probably quote those for the shell.

To use this feature from a browser, add a bookmark with an arbitrary
name, e.g., =Org: store-link= and enter this as /Location/:

#+begin_example
javascript:location.href='org-protocol://store-link?' +
      new URLSearchParams({url:location.href, title:document.title});
#+end_example

Title is an optional parameter.  Another expression was recommended earlier:

#+begin_example
javascript:location.href='org-protocol://store-link?url='+
      encodeURIComponent(location.href);
#+end_example

The latter form is compatible with older Org versions from 9.0 to 9.4.

*** The ~capture~ protocol
:PROPERTIES:
:DESCRIPTION: Fill a buffer with external information.
:END:
#+cindex: capture protocol
#+cindex: protocol, capture

Activating the "capture" handler pops up a =Capture= buffer in Emacs,
using acapture template.

: emacsclient "org-protocol://capture?template=X&url=URL&title=TITLE&body=BODY"

To use this feature, add a bookmark with an arbitrary name, e.g.,
=Org: capture=, and enter this as =Location=:

#+begin_example
javascript:location.href='org-protocol://capture?' +
      new URLSearchParams({
            template: 'x', url: window.location.href,
            title: document.title, body: window.getSelection()});
#+end_example

You might have seen another expression:

#+begin_example
javascript:location.href='org-protocol://capture?template=x'+
      '&url='+encodeURIComponent(window.location.href)+
      '&title='+encodeURIComponent(document.title)+
      '&body='+encodeURIComponent(window.getSelection());
#+end_example

It is a bit more cluttered than the former one, but it is compatible
with previous Org versions 9.0-9.4.  In these versions encoding of
space as "+" character was not supported by URI decoder.

#+vindex: org-protocol-default-template-key
The capture template to be used can be specified in the bookmark (like
=X= above).  If unspecified, the template key is set in the variable
~org-protocol-default-template-key~.  The following template
placeholders are available:

#+begin_example
%:link          The URL
%:description   The webpage title
%:annotation    Equivalent to [[%:link][%:description]]
%i              The selected text
#+end_example

*** The ~open-source~ protocol
:PROPERTIES:
:DESCRIPTION: Edit published contents.
:END:
#+cindex: open-source protocol
#+cindex: protocol, open-source

The ~open-source~ handler is designed to help with editing local
sources when reading a document.  To that effect, you can use
a bookmark with the following location:

#+begin_example
javascript:location.href='org-protocol://open-source?&url='+
      encodeURIComponent(location.href)
#+end_example

#+vindex: org-protocol-project-alist
The variable ~org-protocol-project-alist~ maps URLs to local file
names, by stripping URL parameters from the end and replacing the
~:base-url~ with ~:working-directory~ and ~:online-suffix~ with
~:working-suffix~.  For example, assuming you own a local copy of
=https://orgmode.org/worg/= contents at =/home/user/worg=, you can set
~org-protocol-project-alist~ to the following

#+begin_src emacs-lisp
(setq org-protocol-project-alist
      '(("Worg"
         :base-url "https://orgmode.org/worg/"
         :working-directory "/home/user/worg/"
         :online-suffix ".html"
         :working-suffix ".org")))
#+end_src

#+texinfo: @noindent
If you are now browsing
=https://orgmode.org/worg/org-contrib/org-protocol.html= and find
a typo or have an idea about how to enhance the documentation, simply
click the bookmark and start editing.

#+cindex: rewritten URL in open-source protocol
#+cindex: protocol, open-source rewritten URL
However, such mapping may not always yield the desired results.
Suppose you maintain an online store located at =https://example.com/=.
The local sources reside in =/home/user/example/=.  It is common
practice to serve all products in such a store through one file and
rewrite URLs that do not match an existing file on the server.  That
way, a request to =https://example.com/print/posters.html= might be
rewritten on the server to something like
=https://example.com/shop/products.php/posters.html.php=.  The
~open-source~ handler probably cannot find a file named
=/home/user/example/print/posters.html.php= and fails.

Such an entry in ~org-protocol-project-alist~ may hold an additional
property ~:rewrites~.  This property is a list of cons cells, each of
which maps a regular expression to a path relative to the
~:working-directory~.

Now map the URL to the path =/home/user/example/products.php= by
adding ~:rewrites~ rules like this:

#+begin_src emacs-lisp
(setq org-protocol-project-alist
      '(("example.com"
         :base-url "https://example.com/"
         :working-directory "/home/user/example/"
         :online-suffix ".php"
         :working-suffix ".php"
         :rewrites (("example.com/print/" . "products.php")
                    ("example.com/$" . "index.php")))))
#+end_src

#+texinfo: @noindent
Since =example.com/$= is used as a regular expression, it maps
=http://example.com/=, =https://example.com=,
=http://www.example.com/= and similar to
=/home/user/example/index.php=.

The ~:rewrites~ rules are searched as a last resort if and only if no
existing file name is matched.

#+cindex: protocol, open-source, set-up mapping
#+cindex: mappings in open-source protocol
#+findex: org-protocol-create
#+findex: org-protocol-create-for-org
Two functions can help you filling ~org-protocol-project-alist~ with
valid contents: ~org-protocol-create~ and
~org-protocol-create-for-org~.  The latter is of use if you're editing
an Org file that is part of a publishing project.
** Org Crypt
:PROPERTIES:
:DESCRIPTION: Encrypting Org files.
:END:

Org Crypt encrypts the text of an entry, but not the headline, or
properties.  Behind the scene, it uses the [[info:epa][Emacs EasyPG Library]] to
encrypt and decrypt files, and EasyPG needs a correct [[info:gnupg][GnuPG]] setup.

#+vindex: org-crypt-tag-matcher
Any text below a headline that has a =crypt= tag is automatically
encrypted when the file is saved.  To use a different tag, customize
the ~org-crypt-tag-matcher~ setting.

Here is a suggestion for Org Crypt settings in Emacs init file:

#+begin_src emacs-lisp
(require 'org-crypt)
(org-crypt-use-before-save-magic)
(setq org-tags-exclude-from-inheritance '("crypt"))

(setq org-crypt-key nil)
;; GPG key to use for encryption.
;; nil means  use symmetric encryption unconditionally.
;; "" means use symmetric encryption unless heading sets CRYPTKEY property.

(setq auto-save-default nil)
;; Auto-saving does not cooperate with org-crypt.el: so you need to
;; turn it off if you plan to use org-crypt.el quite often.  Otherwise,
;; you'll get an (annoying) message each time you start Org.

;; To turn it off only locally, you can insert this:
;;
;; # -*- buffer-auto-save-file-name: nil; -*-
#+end_src

It's possible to use different keys for different headings by
specifying the respective key as property =CRYPTKEY=, e.g.:

#+begin_example
,* Totally secret :crypt:
  :PROPERTIES:
  :CRYPTKEY: 0x0123456789012345678901234567890123456789
  :END:
#+end_example

Note that =CRYPTKEY= property is only effective when ~org-crypt-key~
is set to non-nil.  ~nil~ value of ~org-crypt-key~ makes Org use
symmetric encryption unconditionally.

Excluding the =crypt= tag from inheritance prevents already encrypted
text from being encrypted again.

** Org Mobile
:PROPERTIES:
:DESCRIPTION: Viewing and capture on a mobile device.
:END:
#+cindex: smartphone

Org Mobile is a protocol for synchronizing Org files between Emacs and
other applications, e.g., on mobile devices.  It enables offline-views
and capture support for an Org mode system that is rooted on a "real"
computer.  The external application can also record changes to
existing entries.

This appendix describes Org's support for agenda view formats
compatible with Org Mobile.  It also describes synchronizing changes,
such as to notes, between the mobile application and the computer.

To change tags and TODO states in the mobile application, first
customize the variables ~org-todo-keywords~, ~org-tag-alist~ and
~org-tag-persistent-alist~.  These should cover all the important tags
and TODO keywords, even if Org files use only some of them.  Though
the mobile application is expected to support in-buffer settings, it
is required to understand TODO states /sets/ (see [[*Setting up keywords
for individual files]]) and /mutually exclusive/ tags (see [[*Setting
Tags]]) only for those set in these variables.

*** Setting up the staging area
:PROPERTIES:
:DESCRIPTION: For the mobile device.
:END:

#+vindex: org-mobile-directory
The mobile application needs access to a file directory on
a server[fn:51] to interact with Emacs.  Pass its location through
the ~org-mobile-directory~ variable.  If you can mount that directory
locally just set the variable to point to that directory:

#+begin_src emacs-lisp
(setq org-mobile-directory "~/orgmobile/")
#+end_src

Alternatively, by using TRAMP (see [[info:tramp][TRAMP User Manual]]),
~org-mobile-directory~ may point to a remote directory accessible
through, for example, SSH, SCP, or DAVS:

#+begin_src emacs-lisp
(setq org-mobile-directory "/davs:user@remote.host:/org/webdav/")
#+end_src

#+vindex: org-mobile-encryption
With a public server, consider encrypting the files.  Org also
requires OpenSSL installed on the local computer.  To turn on
encryption, set the same password in the mobile application and in
Emacs.  Set the password in the variable
~org-mobile-use-encryption~[fn:: If Emacs is configured for safe
storing of passwords, then configure the variable
~org-mobile-encryption-password~; please read the docstring of that
variable.].  Note that even after the mobile application encrypts the
file contents, the file name remains visible on the file systems of
the local computer, the server, and the mobile device.

*** Pushing to the mobile application
:PROPERTIES:
:DESCRIPTION: Uploading Org files and agendas.
:END:

#+findex: org-mobile-push
#+vindex: org-mobile-files
The command ~org-mobile-push~ copies files listed in
~org-mobile-files~ into the staging area.  Files include agenda files
(as listed in ~org-agenda-files~).  Customize ~org-mobile-files~ to
add other files.  File names are staged with paths relative to
~org-directory~, so all files should be inside this directory[fn::
Symbolic links in ~org-directory~ need to have the same name as their
targets.].

Push creates a special Org file =agendas.org= with custom agenda views
defined by the user[fn:52].

Finally, Org writes the file =index.org=, containing links to other
files.  The mobile application reads this file first from the server
to determine what other files to download for agendas.  For faster
downloads, it is expected to only read files whose checksums[fn::
Checksums are stored automatically in the file =checksums.dat=.]  have
changed.

*** Pulling from the mobile application
:PROPERTIES:
:DESCRIPTION: Integrating captured and flagged items.
:END:

#+findex: org-mobile-pull
The command ~org-mobile-pull~ synchronizes changes with the server.
More specifically, it first pulls the Org files for viewing.  It then
appends captured entries and pointers to flagged or changed entries to
the file =mobileorg.org= on the server.  Org ultimately integrates its
data in an inbox file format, through the following steps:

1.
   #+vindex: org-mobile-inbox-for-pull
   Org moves all entries found in =mobileorg.org=[fn:: The file will
   be empty after this operation.] and appends them to the file
   pointed to by the variable ~org-mobile-inbox-for-pull~.  It should
   reside neither in the staging area nor on the server.  Each
   captured entry and each editing event is a top-level entry in the
   inbox file.

2.
   #+cindex: @samp{FLAGGED}, tag
   After moving the entries, Org processes changes to the shared
   files.  Some of them are applied directly and without user
   interaction.  Examples include changes to tags, TODO state,
   headline and body text.  Entries requiring further action are
   tagged as =FLAGGED=.  Org marks entries with problems with an error
   message in the inbox.  They have to be resolved manually.

3. Org generates an agenda view for flagged entries for user
   intervention to clean up.  For notes stored in flagged entries, Org
   displays them in the echo area when point is on the corresponding
   agenda item.

   - {{{kbd(?)}}} ::

     Pressing {{{kbd(?)}}} displays the entire flagged note in another
     window.  Org also pushes it to the kill ring.  To store flagged
     note as a normal note, use {{{kbd(? z C-y C-c C-c)}}}.  Pressing
     {{{kbd(?)}}} twice does these things: first it removes the
     =FLAGGED= tag; second, it removes the flagged note from the
     property drawer; third, it signals that manual editing of the
     flagged entry is now finished.

#+kindex: ? @r{(Agenda dispatcher)}
From the agenda dispatcher, {{{kbd(?)}}} returns to the view to finish
processing flagged entries.  Note that these entries may not be the
most recent since the mobile application searches files that were last
pulled.  To get an updated agenda view with changes since the last
pull, pull again.

* Hacking
:PROPERTIES:
:DESCRIPTION: How to hack your way around.
:APPENDIX: t
:END:
#+cindex: hacking

This appendix describes some ways a user can extend the functionality
of Org.

** Hooks
:PROPERTIES:
:DESCRIPTION: How to reach into Org's internals.
:END:
#+cindex: hooks

Org has a large number of hook variables for adding functionality.
This appendix illustrates using a few.  A complete list of hooks with
documentation is maintained by the Worg project at
https://orgmode.org/worg/doc.html#hooks.

** Add-on Packages
:PROPERTIES:
:DESCRIPTION: Available extensions.
:END:
#+cindex: add-on packages

Various authors wrote a large number of add-on packages for Org.  Some
of these packages used to be part of the =org-mode= repository but are
now hosted in a separate =org-contrib= repository
[[https://git.sr.ht/~bzg/org-contrib][here]].  A Worg page with more
information is at: https://orgmode.org/worg/org-contrib/.

** Adding Hyperlink Types
:PROPERTIES:
:DESCRIPTION: New custom link types.
:END:
#+cindex: hyperlinks, adding new types

Org has many built-in hyperlink types (see [[*Hyperlinks]]), and an
interface for adding new link types.  The following example shows the
process of adding Org links to Unix man pages, which look like this

: [[man:printf][The printf manual]]

#+texinfo: @noindent
The following =ol-man.el= file implements it

#+begin_src emacs-lisp
;;; ol-man.el - Support for links to man pages in Org mode
(require 'ol)

(org-link-set-parameters "man"
                         :follow #'org-man-open
                         :export #'org-man-export
                         :store #'org-man-store-link)

(defcustom org-man-command 'man
  "The Emacs command to be used to display a man page."
  :group 'org-link
  :type '(choice (const man) (const woman)))

(defun org-man-open (path _)
  "Visit the manpage on PATH.
PATH should be a topic that can be thrown at the man command."
  (funcall org-man-command path))

(defun org-man-store-link ()
  "Store a link to a man page."
  (when (memq major-mode '(Man-mode woman-mode))
    ;; This is a man page, we do make this link.
    (let* ((page (org-man-get-page-name))
           (link (concat "man:" page))
           (description (format "Man page for %s" page)))
      (org-link-store-props
       :type "man"
       :link link
       :description description))))

(defun org-man-get-page-name ()
  "Extract the page name from the buffer name."
  ;; This works for both `Man-mode' and `woman-mode'.
  (if (string-match " \\(\\S-+\\)\\*" (buffer-name))
      (match-string 1 (buffer-name))
    (error "Cannot create link to this man page")))

(defun org-man-export (link description format _)
  "Export a man page link from Org files."
  (let ((path (format "http://man.he.net/?topic=%s&section=all" link))
        (desc (or description link)))
    (pcase format
      (`html (format "<a target=\"_blank\" href=\"%s\">%s</a>" path desc))
      (`latex (format "\\href{%s}{%s}" path desc))
      (`texinfo (format "@uref{%s,%s}" path desc))
      (`ascii (format "%s (%s)" desc path))
      (t path))))

(provide ol-man)
;;; ol-man.el ends here
#+end_src

#+texinfo: @noindent
To activate links to man pages in Org, enter this in the Emacs init
file:

#+begin_src emacs-lisp
(require 'ol-man)
#+end_src

#+texinfo: @noindent
A review of =ol-man.el=:

1. First, =(require 'ol)= ensures that =ol.el= is loaded.

2.

   #+findex: org-link-set-parameters
   #+vindex: org-link-parameters
   Then ~org-link-set-parameters~ defines a new link type with =man=
   prefix and associates functions for following, exporting and
   storing such links.  See the variable ~org-link-parameters~ for
   a complete list of possible associations.

3. The rest of the file implements necessary variables and functions.

   For example, ~org-man-store-link~ is responsible for storing a link
   when ~org-store-link~ (see [[*Handling Links]]) is called from a buffer
   displaying a man page.  It first checks if the major mode is
   appropriate.  If check fails, the function returns ~nil~, which
   means it isn't responsible for creating a link to the current
   buffer.  Otherwise the function makes a link string by combining
   the =man:= prefix with the man topic.  It also provides a default
   description.  The function ~org-insert-link~ can insert it back
   into an Org buffer later on.

** Adding Export Back-ends
:PROPERTIES:
:DESCRIPTION: How to write new export back-ends.
:END:
#+cindex: Export, writing back-ends

Org's export engine makes it easy for writing new back-ends.  The
framework on which the engine was built makes it easy to derive new
back-ends from existing ones.

#+findex: org-export-define-backend
#+findex: org-export-define-derived-backend
The two main entry points to the export engine are:
~org-export-define-backend~ and ~org-export-define-derived-backend~.
To grok these functions, see =ox-latex.el= for an example of defining
a new back-end from scratch, and =ox-beamer.el= for an example of
deriving from an existing engine.

For creating a new back-end from scratch, first set its name as
a symbol in an alist consisting of elements and export functions.  To
make the back-end visible to the export dispatcher, set ~:menu-entry~
keyword.  For export options specific to this back-end, set the
~:options-alist~.

For creating a new back-end from an existing one, set
~:translate-alist~ to an alist of export functions.  This alist
replaces the parent back-end functions.

For complete documentation, see [[https://orgmode.org/worg/dev/org-export-reference.html][the Org Export Reference on Worg]].

** Tables in Arbitrary Syntax
:PROPERTIES:
:DESCRIPTION: Orgtbl for LaTeX and other programs.
:END:
#+cindex: tables, in other modes
#+cindex: lists, in other modes
#+cindex: Orgtbl mode

Due to Org's success in handling tables with Orgtbl, a frequently
requested feature is the use of Org's table functions in other modes,
e.g., LaTeX.  This would be hard to do in a general way without
complicated customization nightmares.  Moreover, that would take Org
away from its simplicity roots that Orgtbl has proven.  There is,
however, an alternate approach to accomplishing the same.

This approach involves implementing a custom /translate/ function that
operates on a native Org /source table/ to produce a table in another
format.  This strategy would keep the excellently working Orgtbl
simple and isolate complications, if any, confined to the translate
function.  To add more alien table formats, we just add more translate
functions.  Also the burden of developing custom translate functions
for new table formats is in the hands of those who know those formats
best.

*** Radio tables
:PROPERTIES:
:DESCRIPTION: Sending and receiving radio tables.
:END:
#+cindex: radio tables

Radio tables are target locations for translated tables that are not near
their source.  Org finds the target location and inserts the translated
table.

The key to finding the target location is the magic words =BEGIN/END
RECEIVE ORGTBL=.  They have to appear as comments in the current mode.
If the mode is C, then:

#+begin_example
/* BEGIN RECEIVE ORGTBL table_name */
/* END RECEIVE ORGTBL table_name */
#+end_example

At the location of source, Org needs a special line to direct Orgtbl
to translate and to find the target for inserting the translated
table.  For example:

#+cindex: @samp{ORGTBL}, keyword
: #+ORGTBL: SEND table_name translation_function arguments ...

#+texinfo: @noindent
=table_name= is the table's reference name, which is also used in the
receiver lines, and the =translation_function= is the Lisp function
that translates.  This line, in addition, may also contain alternating
key and value arguments at the end.  The translation function gets
these values as a property list.  A few standard parameters are
already recognized and acted upon before the translation function is
called:

- =:skip N= ::

  Skip the first N lines of the table.  Hlines do count; include them
  if they are to be skipped.

- =:skipcols (n1 n2 ...)= ::

  List of columns to be skipped.  First Org automatically discards
  columns with calculation marks and then sends the table to the
  translator function, which then skips columns as specified in
  =skipcols=.

To keep the source table intact in the buffer without being disturbed
when the source file is compiled or otherwise being worked on, use one
of these strategies:

- Place the table in a block comment.  For example, in C mode you
  could wrap the table between =/*= and =*/= lines.

- Put the table after an "end" statement.  For example ~\bye~ in TeX
  and ~\end{document}~ in LaTeX.

- Comment and un-comment each line of the table during edits.  The
  {{{kbd(M-x orgtbl-toggle-comment)}}} command makes toggling easy.

*** A LaTeX example of radio tables
:PROPERTIES:
:DESCRIPTION: Step by step, almost a tutorial.
:ALT_TITLE: A LaTeX example
:END:
#+cindex: @LaTeX{}, and Orgtbl mode

To wrap a source table in LaTeX, use the =comment= environment
provided by =comment.sty=[fn:: https://www.ctan.org/pkg/comment].  To
activate it, put ~\usepackage{comment}~ in the document header.
Orgtbl mode inserts a radio table skeleton[fn:53] with the command
{{{kbd(M-x orgtbl-insert-radio-table)}}}, which prompts for a table
name.  For example, if =salesfigures= is the name, the template
inserts:

#+begin_example
% BEGIN RECEIVE ORGTBL salesfigures
% END RECEIVE ORGTBL salesfigures
\begin{comment}
,#+ORGTBL: SEND salesfigures orgtbl-to-latex
| | |
\end{comment}
#+end_example

#+vindex: LaTeX-verbatim-environments
#+texinfo: @noindent
The line =#+ORGTBL: SEND= tells Orgtbl mode to use the function
~orgtbl-to-latex~ to convert the table to LaTeX format, then insert
the table at the target (receive) location named =salesfigures=.  Now
the table is ready for data entry.  It can even use spreadsheet
features[fn:54]:

#+begin_example
% BEGIN RECEIVE ORGTBL salesfigures
% END RECEIVE ORGTBL salesfigures
\begin{comment}
,#+ORGTBL: SEND salesfigures orgtbl-to-latex
| Month | Days | Nr sold | per day |
|-------+------+---------+---------|
| Jan   |   23 |      55 |     2.4 |
| Feb   |   21 |      16 |     0.8 |
| March |   22 |     278 |    12.6 |
,#+TBLFM: $4=$3/$2;%.1f
% $ (optional extra dollar to keep Font Lock happy, see footnote)
\end{comment}
#+end_example

After editing, {{{kbd(C-c C-c)}}} inserts the translated table at the
target location, between the two marker lines.

For hand-made custom tables, note that the translator needs to skip
the first two lines of the source table.  Also the command has to
/splice/ out the target table without the header and footer.

#+begin_example
\begin{tabular}{lrrr}
Month & \multicolumn{1}{c}{Days} & Nr.\ sold & per day\\
% BEGIN RECEIVE ORGTBL salesfigures
% END RECEIVE ORGTBL salesfigures
\end{tabular}
%
\begin{comment}
,#+ORGTBL: SEND salesfigures orgtbl-to-latex :splice t :skip 2
| Month | Days | Nr sold | per day |
|-------+------+---------+---------|
| Jan   |   23 |      55 |     2.4 |
| Feb   |   21 |      16 |     0.8 |
| March |   22 |     278 |    12.6 |
,#+TBLFM: $4=$3/$2;%.1f
\end{comment}
#+end_example

The LaTeX translator function ~orgtbl-to-latex~ is already part of
Orgtbl mode and uses a =tabular= environment to typeset the table and
marks horizontal lines with ~\hline~.  For additional parameters to
control output, see [[*Translator functions]]:

- =:splice BOOLEAN= ::

  When {{{var(BOOLEAN}}} is non-~nil~, return only table body lines;
  i.e., not wrapped in =tabular= environment.  Default is ~nil~.

- =:fmt FMT= ::

  Format string to warp each field.  It should contain =%s= for the
  original field value.  For example, to wrap each field value in
  dollar symbol, you could use =:fmt "$%s$"=.  Format can also wrap
  a property list with column numbers and formats, for example =:fmt
  (2 "$%s$" 4 "%s\\%%")=.  In place of a string, a function of one
  argument can be used; the function must return a formatted string.

- =:efmt EFMT= ::

  Format numbers as exponentials.  The spec should have =%s= twice for
  inserting mantissa and exponent, for example ="%s\\times10^{%s}"=.  This
  may also be a property list with column numbers and formats, for
  example =:efmt (2 "$%s\\times10^{%s}$" 4 "$%s\\cdot10^{%s}$")=.  After
  {{{var(EFMT)}}} has been applied to a value, {{{var(FMT)}}}---see
  above---is also applied.  Functions with two arguments can be
  supplied instead of strings.  By default, no special formatting is
  applied.

*** Translator functions
:PROPERTIES:
:DESCRIPTION: Copy and modify.
:END:
#+cindex: HTML, and Orgtbl mode
#+cindex: translator function

#+findex: orgtbl-to-csv
#+findex: orgtbl-to-tsv
#+findex: orgtbl-to-latex
#+findex: orgtbl-to-html
#+findex: orgtbl-to-texinfo
#+findex: orgtbl-to-unicode
#+findex: orgtbl-to-orgtbl
#+findex: orgtbl-to-generic
Orgtbl mode has built-in translator functions: ~orgtbl-to-csv~
(comma-separated values), ~orgtbl-to-tsv~ (TAB-separated values),
~orgtbl-to-latex~, ~orgtbl-to-html~, ~orgtbl-to-texinfo~,
~orgtbl-to-unicode~ and ~orgtbl-to-orgtbl~.  They use the generic
translator, ~orgtbl-to-generic~, which delegates translations to
various export back-ends.

Properties passed to the function through the =ORGTBL SEND= line take
precedence over properties defined inside the function.  For example,
this overrides the default LaTeX line endings, ~\\~, with ~\\[2mm]~:

: #+ORGTBL: SEND test orgtbl-to-latex :lend " \\\\[2mm]"

For a new language translator, define a converter function.  It can be
a generic function, such as shown in this example.  It marks
a beginning and ending of a table with =!BTBL!= and =!ETBL!=;
a beginning and ending of lines with =!BL!= and =!EL!=; and uses a TAB
for a field separator:

#+begin_src emacs-lisp
(defun orgtbl-to-language (table params)
  "Convert the orgtbl-mode TABLE to language."
  (orgtbl-to-generic
   table
   (org-combine-plists
    '(:tstart "!BTBL!" :tend "!ETBL!" :lstart "!BL!" :lend "!EL!" :sep "\t")
    params)))
#+end_src

#+texinfo: @noindent
The documentation for the ~orgtbl-to-generic~ function shows
a complete list of parameters, each of which can be passed through to
~orgtbl-to-latex~, ~orgtbl-to-texinfo~, and any other function using
that generic function.

For complicated translations the generic translator function could be
replaced by a custom translator function.  Such a custom function must
take two arguments and return a single string containing the formatted
table.  The first argument is the table whose lines are a list of
fields or the symbol ~hline~.  The second argument is the property
list consisting of parameters specified in the =#+ORGTBL: SEND= line.
Please share your translator functions by posting them to the Org
users mailing list, at mailto:emacs-orgmode@gnu.org.

** Dynamic Blocks
:PROPERTIES:
:DESCRIPTION: Automatically filled blocks.
:END:
#+cindex: dynamic blocks

Org supports /dynamic blocks/ in Org documents.  They are inserted
with begin and end markers like any other code block, but the contents
are updated automatically by a user function.

#+kindex: C-c C-x x
#+findex: org-dynamic-block-insert-dblock
You can insert a dynamic block with ~org-dynamic-block-insert-dblock~,
which is bound to {{{kbd(C-c C-x x)}}} by default.  For example,
{{{kbd(C-c C-x x c l o c k t a b l e RET)}}} inserts a table that
updates the work time (see [[*Clocking Work Time]]).

Dynamic blocks can have names and function parameters.  The syntax is
similar to source code block specifications:

#+begin_example
,#+BEGIN: myblock :parameter1 value1 :parameter2 value2 ...
  ...
,#+END:
#+end_example

These commands update dynamic blocks:

- {{{kbd(C-c C-x C-u)}}} (~org-dblock-update~) ::

  #+kindex: C-c C-x C-u
  #+findex: org-dblock-update
  Update dynamic block at point.

- {{{kbd(C-u C-c C-x C-u)}}} ::

  #+kindex: C-u C-c C-x C-u
  Update all dynamic blocks in the current file.

Before updating a dynamic block, Org removes content between the
=BEGIN= and =END= markers.  Org then reads the parameters on the
=BEGIN= line for passing to the writer function as a plist.  The
previous content of the dynamic block becomes erased from the buffer
and appended to the plist under ~:content~.

The syntax for naming a writer function with a dynamic block labeled
=myblock= is: ~org-dblock-write:myblock~.

The following is an example of a dynamic block and a block writer function
that updates the time when the function was last run:

#+begin_example
,#+BEGIN: block-update-time :format "on %m/%d/%Y at %H:%M"
  ...
,#+END:
#+end_example

#+texinfo: @noindent
The dynamic block's writer function:

#+begin_src emacs-lisp
(defun org-dblock-write:block-update-time (params)
  (let ((fmt (or (plist-get params :format) "%d. %m. %Y")))
    (insert "Last block update at: "
            (format-time-string fmt))))
#+end_src

To keep dynamic blocks up-to-date in an Org file, use the function,
~org-update-all-dblocks~ in hook, such as ~before-save-hook~.  The
~org-update-all-dblocks~ function does not run if the file is not in
Org mode.

#+findex: org-narrow-to-block
Dynamic blocks, like any other block, can be narrowed with
~org-narrow-to-block~.

** Special Agenda Views
:PROPERTIES:
:DESCRIPTION: Customized views.
:END:
#+cindex: agenda views, user-defined

#+vindex: org-agenda-skip-function
#+vindex: org-agenda-skip-function-global
Org provides a special hook to further limit items in agenda views:
~agenda~, ~agenda*~[fn:: The ~agenda*~ view is the same as ~agenda~
except that it only considers /appointments/, i.e., scheduled and
deadline items that have a time specification =[h]h:mm= in their
time-stamps.], ~todo~, ~alltodo~, ~tags~, ~tags-todo~, ~tags-tree~.
Specify a custom function that tests inclusion of every matched item
in the view.  This function can also skip as much as is needed.

For a global condition applicable to agenda views, use the
~org-agenda-skip-function-global~ variable.  Org uses a global
condition with ~org-agenda-skip-function~ for custom searching.

This example defines a function for a custom view showing TODO items
with =waiting= status.  Manually this is a multi-step search process,
but with a custom view, this can be automated as follows:

The custom function searches the subtree for the =waiting= tag and
returns ~nil~ on match.  Otherwise it gives the location from where
the search continues.

#+begin_src emacs-lisp
(defun my-skip-unless-waiting ()
  "Skip trees that are not waiting"
  (let ((subtree-end (save-excursion (org-end-of-subtree t))))
    (if (re-search-forward ":waiting:" subtree-end t)
        nil          ; tag found, do not skip
      subtree-end))) ; tag not found, continue after end of subtree
#+end_src

To use this custom function in a custom agenda command:

#+begin_src emacs-lisp
(org-add-agenda-custom-command
 '("b" todo "PROJECT"
   ((org-agenda-skip-function 'my-skip-unless-waiting)
    (org-agenda-overriding-header "Projects waiting for something: "))))
#+end_src

#+vindex: org-agenda-overriding-header
Note that this also binds ~org-agenda-overriding-header~ to a more
meaningful string suitable for the agenda view.

#+vindex: org-odd-levels-only
#+vindex: org-agenda-skip-function
#+findex: org-agenda-skip-entry-if
#+findex: org-agenda-skip-subtree-if
Search for entries with a limit set on levels for the custom search.
This is a general approach to creating custom searches in Org.  To
include all levels, use =LEVEL>0=[fn:: Note that, for
~org-odd-levels-only~, a level number corresponds to order in the
hierarchy, not to the number of stars.].  Then to selectively pick the
matched entries, use ~org-agenda-skip-function~, which also accepts
Lisp forms, such as ~org-agenda-skip-entry-if~ and
~org-agenda-skip-subtree-if~.  For example:

- =(org-agenda-skip-entry-if 'scheduled)= ::

  Skip current entry if it has been scheduled.

- =(org-agenda-skip-entry-if 'notscheduled)= ::

  Skip current entry if it has not been scheduled.

- =(org-agenda-skip-entry-if 'deadline)= ::

  Skip current entry if it has a deadline.

- =(org-agenda-skip-entry-if 'scheduled 'deadline)= ::

  Skip current entry if it has a deadline, or if it is scheduled.

- =(org-agenda-skip-entry-if 'todo '("TODO" "WAITING"))= ::

  Skip current entry if the TODO keyword is TODO or WAITING.

- =(org-agenda-skip-entry-if 'todo 'done)= ::

  Skip current entry if the TODO keyword marks a DONE state.

- =(org-agenda-skip-entry-if 'timestamp)= ::

  Skip current entry if it has any timestamp, may also be deadline or
  scheduled.

- =(org-agenda-skip-entry-if 'regexp "regular expression")= ::

  Skip current entry if the regular expression matches in the entry.

- =(org-agenda-skip-entry-if 'notregexp "regular expression")= ::

  Skip current entry unless the regular expression matches.

- =(org-agenda-skip-subtree-if 'regexp "regular expression")= ::

  Same as above, but check and skip the entire subtree.

The following is an example of a search for =waiting= without the
special function:

#+begin_src emacs-lisp
(org-add-agenda-custom-command
 '("b" todo "PROJECT"
   ((org-agenda-skip-function '(org-agenda-skip-subtree-if
                                'regexp ":waiting:"))
    (org-agenda-overriding-header "Projects waiting for something: "))))
#+end_src

** Speeding Up Your Agendas
:PROPERTIES:
:DESCRIPTION: Tips on how to speed up your agendas.
:END:
#+cindex: agenda views, optimization

Some agenda commands slow down when the Org files grow in size or
number.  Here are tips to speed up:

- Reduce the number of Org agenda files to avoid slowdowns due to hard drive
  accesses.

- Reduce the number of DONE and archived headlines so agenda
  operations that skip over these can finish faster.

- Do not dim blocked tasks:
  #+vindex: org-agenda-dim-blocked-tasks

  #+begin_src emacs-lisp
  (setq org-agenda-dim-blocked-tasks nil)
  #+end_src

- Stop preparing agenda buffers on startup:
  #+vindex: org-startup-folded
  #+vindex: org-agenda-inhibit-startup

  #+begin_src emacs-lisp
  (setq org-agenda-inhibit-startup t)
  #+end_src

- Disable tag inheritance for agendas:
  #+vindex: org-agenda-show-inherited-tags
  #+vindex: org-agenda-use-tag-inheritance

  #+begin_src emacs-lisp
  (setq org-agenda-use-tag-inheritance nil)
  #+end_src

  #+vindex: org-agenda-ignore-properties
- Disable parsing of some drawer properties:

  #+begin_src emacs-lisp
  (setq org-agenda-ignore-properties '(effort appt stats category))
  #+end_src

  The drawer properties you can disable in the agenda are effort
  estimates (~effort~), appointments (~appt~), statistics (~stats~)
  and subtree-local categories (~category~).

These options can be applied to selected agenda views.  For more
details about generation of agenda views, see the docstrings for the
relevant variables, and this [[https://orgmode.org/worg/agenda-optimization.html][dedicated Worg page]] for agenda
optimization.

** Extracting Agenda Information
:PROPERTIES:
:DESCRIPTION: Post-processing agenda information.
:END:
#+cindex: agenda, pipe
#+cindex: scripts, for agenda processing

Org provides commands to access agendas through Emacs batch mode.
Through this command-line interface, agendas are automated for further
processing or printing.

#+vindex: org-agenda-custom-commands
#+findex: org-batch-agenda
~org-batch-agenda~ creates an agenda view in ASCII and outputs to
standard output.  This command takes one string parameter.  When
string consists of a single character, Org uses it as a key to
~org-agenda-custom-commands~.  These are the same ones available
through the agenda dispatcher (see [[*The Agenda Dispatcher]]).

This example command line directly prints the TODO list to the printer:

: emacs -batch -l ~/.emacs -eval '(org-batch-agenda "t")' | lpr

When the string parameter length is two or more characters, Org
matches it with tags/TODO strings.  For example, this example command
line prints items tagged with =shop=, but excludes items tagged with
=NewYork=:

#+begin_example
emacs -batch -l ~/.emacs                                      \
      -eval '(org-batch-agenda "+shop-NewYork")' | lpr
#+end_example

#+texinfo: @noindent
An example showing on-the-fly parameter modifications:

#+begin_example
emacs -batch -l ~/.emacs                                      \
   -eval '(org-batch-agenda "a"                               \
           org-agenda-span (quote month)                      \
           org-agenda-include-diary nil                       \
           org-agenda-files (quote ("~/org/project.org")))'   \
   | lpr
#+end_example

#+texinfo: @noindent
which produces an agenda for the next 30 days from just the
=~/org/projects.org= file.

#+findex: org-batch-agenda-csv
For structured processing of agenda output, use ~org-batch-agenda-csv~
with the following fields:

- category :: The category of the item
- head :: The headline, without TODO keyword, TAGS and PRIORITY
- type :: The type of the agenda entry, can be

  | ~todo~              | selected in TODO match              |
  | ~tagsmatch~         | selected in tags match              |
  | ~diary~             | imported from diary                 |
  | ~deadline~          | a deadline                          |
  | ~scheduled~         | scheduled                           |
  | ~timestamp~         | appointment, selected by timestamp  |
  | ~closed~            | entry was closed on date            |
  | ~upcoming-deadline~ | warning about nearing deadline      |
  | ~past-scheduled~    | forwarded scheduled item            |
  | ~block~             | entry has date block including date |

- todo :: The TODO keyword, if any
- tags :: All tags including inherited ones, separated by colons
- date :: The relevant date, like =2007-2-14=
- time :: The time, like =15:00-16:50=
- extra :: String with extra planning info
- priority-l :: The priority letter if any was given
- priority-n :: The computed numerical priority

If the selection of the agenda item was based on a timestamp,
including those items with =DEADLINE= and =SCHEDULED= keywords, then
Org includes date and time in the output.

If the selection of the agenda item was based on a timestamp  (or
deadline/scheduled), then Org includes date and time in the output.

Here is an example of a post-processing script in Perl.  It takes the
CSV output from Emacs and prints with a checkbox:

#+begin_src perl
#!/usr/bin/perl

# define the Emacs command to run
$cmd = "emacs -batch -l ~/.emacs -eval '(org-batch-agenda-csv \"t\")'";

# run it and capture the output
$agenda = qx{$cmd 2>/dev/null};

# loop over all lines
foreach $line (split(/\n/,$agenda)) {
    # get the individual values
    ($category,$head,$type,$todo,$tags,$date,$time,$extra,
     $priority_l,$priority_n) = split(/,/,$line);
    # process and print
    print "[ ] $head\n";
}
#+end_src

** Using the Property API
:PROPERTIES:
:DESCRIPTION: Writing programs that use entry properties.
:END:
#+cindex: API, for properties
#+cindex: properties, API

Here is a description of the functions that can be used to work with
properties.

#+attr_texinfo: :options org-entry-properties &optional pom which
#+begin_defun
Get all properties of the entry at point-or-marker {{{var(POM)}}}.
This includes the TODO keyword, the tags, time strings for deadline,
scheduled, and clocking, and any additional properties defined in the
entry.  The return value is an alist.  Keys may occur multiple times
if the property key was used several times.  {{{var(POM)}}} may also
be ~nil~, in which case the current entry is used.  If
{{{var(WHICH)}}} is ~nil~ or ~all~, get all properties.  If
{{{var(WHICH)}}} is ~special~ or ~standard~, only get that subclass.
#+end_defun

#+vindex: org-use-property-inheritance
#+findex: org-insert-property-drawer
#+attr_texinfo: :options org-entry-get pom property &optional inherit
#+begin_defun
Get value of {{{var(PROPERTY)}}} for entry at point-or-marker
{{{var(POM)}}}.  By default, this only looks at properties defined
locally in the entry.  If {{{var(INHERIT)}}} is non-~nil~ and the
entry does not have the property, then also check higher levels of the
hierarchy.  If {{{var(INHERIT)}}} is the symbol ~selective~, use
inheritance if and only if the setting of
~org-use-property-inheritance~ selects {{{var(PROPERTY)}}} for
inheritance.
#+end_defun

#+attr_texinfo: :options org-entry-delete pom property
#+begin_defun
Delete the property {{{var(PROPERTY)}}} from entry at point-or-marker
{{{var(POM)}}}.
#+end_defun

#+attr_texinfo: :options org-entry-put pom property value
#+begin_defun
Set {{{var(PROPERTY)}}} to {{{var(VALUES)}}} for entry at
point-or-marker POM.
#+end_defun

#+attr_texinfo: :options org-buffer-property-keys &optional include-specials
#+begin_defun
Get all property keys in the current buffer.
#+end_defun

#+attr_texinfo: :options org-insert-property-drawer
#+begin_defun
Insert a property drawer for the current entry.  Also
#+end_defun

#+attr_texinfo: :options org-entry-put-multivalued-property pom property &rest values
#+begin_defun
Set {{{var(PROPERTY)}}} at point-or-marker {{{var(POM)}}} to
{{{var(VALUES)}}}.  {{{var(VALUES)}}} should be a list of strings.
They are concatenated, with spaces as separators.
#+end_defun

#+attr_texinfo: :options org-entry-get-multivalued-property pom property
#+begin_defun
Treat the value of the property {{{var(PROPERTY)}}} as
a whitespace-separated list of values and return the values as a list
of strings.
#+end_defun

#+attr_texinfo: :options org-entry-add-to-multivalued-property pom property value
#+begin_defun
Treat the value of the property {{{var(PROPERTY)}}} as
a whitespace-separated list of values and make sure that
{{{var(VALUE)}}} is in this list.
#+end_defun

#+attr_texinfo: :options org-entry-remove-from-multivalued-property pom property value
#+begin_defun
Treat the value of the property {{{var(PROPERTY)}}} as
a whitespace-separated list of values and make sure that
{{{var(VALUE)}}} is /not/ in this list.
#+end_defun

#+attr_texinfo: :options org-entry-member-in-multivalued-property pom property value
#+begin_defun
Treat the value of the property {{{var(PROPERTY)}}} as
a whitespace-separated list of values and check if {{{var(VALUE)}}} is
in this list.
#+end_defun

#+attr_texinfo: :options org-property-allowed-value-functions
#+begin_defopt
Hook for functions supplying allowed values for a specific property.
The functions must take a single argument, the name of the property,
and return a flat list of allowed values.  If =:ETC= is one of the
values, use the values as completion help, but allow also other values
to be entered.  The functions must return ~nil~ if they are not
responsible for this property.
#+end_defopt

** Using the Mapping API
:PROPERTIES:
:DESCRIPTION: Mapping over all or selected entries.
:END:
#+cindex: API, for mapping
#+cindex: mapping entries, API

Org has sophisticated mapping capabilities to find all entries
satisfying certain criteria.  Internally, this functionality is used
to produce agenda views, but there is also an API that can be used to
execute arbitrary functions for each or selected entries.  The main
entry point for this API is:

#+attr_texinfo: :options org-map-entries func &optional match scope &rest skip
#+begin_defun
Call {{{var(FUNC)}}} at each headline selected by {{{var(MATCH)}}} in
{{{var(SCOPE)}}}.

{{{var(FUNC)}}} is a function or a Lisp form.  With point positioned
at the beginning of the headline, call the function without arguments.
Org returns a list of return values of calls to the function.

To avoid preserving point, Org wraps the call to {{{var(FUNC)}}} in
~save-excursion~ form.  After evaluation, Org moves point to the end
of the line that was just processed.  Search continues from that point
forward.  This may not always work as expected under some conditions,
such as if the current subtree was removed by a previous archiving
operation.  In such rare circumstances, Org skips the next entry
entirely when it should not.  To stop Org from such skips, make
{{{var(FUNC)}}} set the variable ~org-map-continue-from~ to a specific
buffer position.

{{{var(MATCH)}}} is a tags/property/TODO match.  Org iterates only
matched headlines.  Org iterates over all headlines when
{{{var(MATCH)}}} is ~nil~ or ~t~.

{{{var(SCOPE)}}} determines the scope of this command.  It can be any
of:

- ~nil~ ::

  The current buffer, respecting the restriction, if any.

- ~tree~ ::

  The subtree started with the entry at point.

- ~region~ ::

  The entries within the active region, if any.

- ~file~ ::

  The current buffer, without restriction.

- ~file-with-archives~ ::

  The current buffer, and any archives associated with it.

- ~agenda~ ::

  All agenda files.

- ~agenda-with-archives~ ::

  All agenda files with any archive files associated with them.

- list of filenames ::

  If this is a list, all files in the list are scanned.

#+texinfo: @noindent
The remaining arguments are treated as settings for the scanner's
skipping facilities.  Valid arguments are:

- ~archive~ ::

  Skip trees with the =ARCHIVE= tag.

- ~comment~ ::

  Skip trees with the COMMENT keyword.

- function or Lisp form ::

  #+vindex: org-agenda-skip-function
  Used as value for ~org-agenda-skip-function~, so whenever the
  function returns ~t~, {{{var(FUNC)}}} is called for that entry and
  search continues from the point where the function leaves it.
#+end_defun

The mapping routine can call any arbitrary function, even functions
that change meta data or query the property API (see [[*Using the
Property API]]).  Here are some handy functions:

#+attr_texinfo: :options org-todo &optional arg
#+begin_defun
Change the TODO state of the entry.  See the docstring of the
functions for the many possible values for the argument
{{{var(ARG)}}}.
#+end_defun

#+attr_texinfo: :options org-priority &optional action
#+begin_defun
Change the priority of the entry.  See the docstring of this function
for the possible values for {{{var(ACTION)}}}.
#+end_defun

#+attr_texinfo: :options org-toggle-tag tag &optional onoff
#+begin_defun
Toggle the tag {{{var(TAG)}}} in the current entry.  Setting
{{{var(ONOFF)}}} to either ~on~ or ~off~ does not toggle tag, but
ensure that it is either on or off.
#+end_defun

#+attr_texinfo: :options org-promote
#+begin_defun
Promote the current entry.
#+end_defun

#+attr_texinfo: :options org-demote
#+begin_defun
Demote the current entry.
#+end_defun

This example turns all entries tagged with =TOMORROW= into TODO
entries with keyword =UPCOMING=.  Org ignores entries in comment trees
and archive trees.

#+begin_src emacs-lisp
(org-map-entries '(org-todo "UPCOMING")
                 "+TOMORROW" 'file 'archive 'comment)
#+end_src

The following example counts the number of entries with TODO keyword
=WAITING=, in all agenda files.

#+begin_src emacs-lisp
(length (org-map-entries t "/+WAITING" 'agenda))
#+end_src

* History and Acknowledgments
:PROPERTIES:
:DESCRIPTION: How Org came into being.
:APPENDIX: t
:END:

** From Carsten
:PROPERTIES:
:UNNUMBERED: notoc
:END:

Org was born in 2003, out of frustration over the user interface of
the Emacs Outline mode.  I was trying to organize my notes and
projects, and using Emacs seemed to be the natural way to go.
However, having to remember eleven different commands with two or
three keys per command, only to hide and show parts of the outline
tree, that seemed entirely unacceptable to me.  Also, when using
outlines to take notes, I constantly wanted to restructure the tree,
organizing it parallel to my thoughts and plans.  /Visibility cycling/
and /structure editing/ were originally implemented in the package
=outline-magic.el=, but quickly moved to the more general =org.el=.
As this environment became comfortable for project planning, the next
step was adding /TODO entries/, basic /timestamps/, and /table
support/.  These areas highlighted the two main goals that Org still
has today: to be a new, outline-based, plain text mode with innovative
and intuitive editing features, and to incorporate project planning
functionality directly into a notes file.

Since the first release, literally thousands of emails to me or to the
[[mailto:emacs-orgmode@gnu.org][mailing list]] have provided a constant stream of bug reports, feedback,
new ideas, and sometimes patches and add-on code.  Many thanks to
everyone who has helped to improve this package.  I am trying to keep
here a list of the people who had significant influence in shaping one
or more aspects of Org.  The list may not be complete, if I have
forgotten someone, please accept my apologies and let me know.

Before I get to this list, a few special mentions are in order:

- Bastien Guerry ::

  Bastien has written a large number of extensions to Org (most of
  them integrated into the core by now), including the LaTeX exporter
  and the plain list parser.  His support during the early days was
  central to the success of this project.  Bastien also invented Worg,
  helped establishing the Web presence of Org, and sponsored hosting
  costs for the orgmode.org website.  Bastien stepped in as maintainer
  of Org between 2011 and 2013, at a time when I desperately needed
  a break.

- Eric Schulte and Dan Davison ::

  Eric and Dan are jointly responsible for the Org Babel system, which
  turns Org into a multi-language environment for evaluating code and
  doing literate programming and reproducible research.  This has
  become one of Org's killer features that define what Org is today.

- John Wiegley ::

  John has contributed a number of great ideas and patches directly to
  Org, including the attachment system (=org-attach.el=), integration
  with Apple Mail (=org-mac-message.el=), hierarchical dependencies of
  TODO items, habit tracking (=org-habits.el=), and encryption
  (=org-crypt.el=).  Also, the capture system is really an extended
  copy of his great =remember.el=.

- Sebastian Rose ::

  Without Sebastian, the HTML/XHTML publishing of Org would be the
  pitiful work of an ignorant amateur.  Sebastian has pushed this part
  of Org onto a much higher level.  He also wrote =org-info.js=,
  a JavaScript program for displaying webpages derived from Org using
  an Info-like or a folding interface with single-key navigation.

See below for the full list of contributions!  Again, please let me
know what I am missing here!

** From Bastien
:PROPERTIES:
:UNNUMBERED: notoc
:END:

I (Bastien) have been maintaining Org between 2011 and 2013.  This
appendix would not be complete without adding a few more
acknowledgments and thanks.

I am first grateful to Carsten for his trust while handing me over the
maintainership of Org.  His unremitting support is what really helped
me getting more confident over time, with both the community and the
code.

When I took over maintainership, I knew I would have to make Org more
collaborative than ever, as I would have to rely on people that are
more knowledgeable than I am on many parts of the code.  Here is
a list of the persons I could rely on, they should really be
considered co-maintainers, either of the code or the community:

- Eric Schulte ::

  Eric is maintaining the Babel parts of Org.  His reactivity here
  kept me away from worrying about possible bugs here and let me focus
  on other parts.

- Nicolas Goaziou ::

  Nicolas is maintaining the consistency of the deepest parts of Org.
  His work on =org-element.el= and =ox.el= has been outstanding, and
  it opened the doors for many new ideas and features.  He rewrote
  many of the old exporters to use the new export engine, and helped
  with documenting this major change.  More importantly (if that's
  possible), he has been more than reliable during all the work done
  for Org 8.0, and always very reactive on the mailing list.

- Achim Gratz ::

  Achim rewrote the building process of Org, turning some /ad hoc/
  tools into a flexible and conceptually clean process.  He patiently
  coped with the many hiccups that such a change can create for users.

- Nick Dokos ::

  The Org mode mailing list would not be such a nice place without
  Nick, who patiently helped users so many times.  It is impossible to
  overestimate such a great help, and the list would not be so active
  without him.

I received support from so many users that it is clearly impossible to
be fair when shortlisting a few of them, but Org's history would not
be complete if the ones above were not mentioned in this manual.

** List of Contributions
:PROPERTIES:
:UNNUMBERED: notoc
:END:

- Russell Adams came up with the idea for drawers.

- Thomas Baumann wrote =ol-bbdb.el= and =ol-mhe.el=.

- Christophe Bataillon created the great unicorn logo that we use on
  the Org mode website.

- Alex Bochannek provided a patch for rounding timestamps.

- Jan Böcker wrote =ol-docview.el=.

- Brad Bozarth showed how to pull RSS feed data into Org files.

- Tom Breton wrote =org-choose.el=.

- Charles Cave's suggestion sparked the implementation of templates
  for Remember, which are now templates for capture.

- Timothy E Chapman worked on a complete overhaul of the orgmode.org
  website in 2020 and helped fixing various bugs.

- Pavel Chalmoviansky influenced the agenda treatment of items with
  specified time.

- Gregory Chernov patched support for Lisp forms into table
  calculations and improved XEmacs compatibility, in particular by
  porting =nouline.el= to XEmacs.

- Sacha Chua suggested copying some linking code from Planner.

- Baoqiu Cui contributed the DocBook exporter.

- Eddward DeVilla proposed and tested checkbox statistics.  He also
  came up with the idea of properties, and that there should be an API
  for them.

- Nick Dokos tracked down several nasty bugs.

- Kees Dullemond used to edit projects lists directly in HTML and so
  inspired some of the early development, including HTML export.  He
  also asked for a way to narrow wide table columns.

- Thomas\nbsp{}S.\nbsp{}Dye contributed documentation on Worg and helped
  integrating the Org Babel documentation into the manual.

- Christian Egli converted the documentation into Texinfo format,
  inspired the agenda, patched CSS formatting into the HTML exporter,
  and wrote =org-taskjuggler.el=.

- David Emery provided a patch for custom CSS support in exported HTML
  agendas.

- Nic Ferrier contributed mailcap and XOXO support.

- Miguel\nbsp{}A.\nbsp{}Figueroa-Villanueva implemented hierarchical checkboxes.

- John Foerch figured out how to make incremental search show context
  around a match in a hidden outline tree.

- Raimar Finken wrote =org-git-line.el=.

- Mikael Fornius works as a mailing list moderator.

- Austin Frank works as a mailing list moderator.

- Eric Fraga drove the development of Beamer export with ideas and
  testing.

- Barry Gidden did proofreading the manual in preparation for the book
  publication through Network Theory Ltd.

- Niels Giesen had the idea to automatically archive DONE trees.

- Nicolas Goaziou rewrote much of the plain list code.

- Kai Grossjohann pointed out key-binding conflicts with other
  packages.

- Brian Gough of Network Theory Ltd publishes the Org mode manual as
  a book.

- Bernt Hansen has driven much of the support for auto-repeating
  tasks, task state change logging, and the clocktable.  His clear
  explanations have been critical when we started to adopt the Git
  version control system.

- Manuel Hermenegildo has contributed various ideas, small fixes and
  patches.

- Phil Jackson wrote =ol-irc.el=.

- Scott Jaderholm proposed footnotes, control over whitespace between
  folded entries, and column view for properties.

- Matt Jones wrote MobileOrg Android.

- Tokuya Kameshima wrote =org-wl.el= and =org-mew.el=.

- Shidai Liu ("Leo") asked for embedded LaTeX and tested it.  He also
  provided frequent feedback and some patches.

- Matt Lundin has proposed last-row references for table formulas and
  named invisible anchors.  He has also worked a lot on the FAQ.

- David Maus wrote =org-atom.el=, maintains the issues file for Org,
  and is a prolific contributor on the mailing list with competent
  replies, small fixes and patches.

- Jason\nbsp{}F.\nbsp{}McBrayer suggested agenda export to CSV format.

- Kyle Meyer helped setting up the [[https://public-inbox.org/][public-inbox]] archive of the [[https://orgmode.org/list/][Org
  mailing list]] and has been fixing many bugs.

- Max Mikhanosha came up with the idea of refiling.

- Dmitri Minaev sent a patch to set priority limits on a per-file
  basis.

- Stefan Monnier provided a patch to keep the Emacs Lisp compiler
  happy.

- Richard Moreland wrote MobileOrg for the iPhone.

- Rick Moynihan proposed allowing multiple TODO sequences in a file
  and being able to quickly restrict the agenda to a subtree.

- Todd Neal provided patches for links to Info files and Elisp forms.

- Greg Newman refreshed the unicorn logo into its current form.

- Tim O'Callaghan suggested in-file links, search options for general
  file links, and tags.

- Osamu Okano wrote =orgcard2ref.pl=, a Perl program to create a text
  version of the reference card.

- Takeshi Okano translated the manual and David O'Toole's tutorial
  into Japanese.

- Oliver Oppitz suggested multi-state TODO items.

- Scott Otterson sparked the introduction of descriptive text for
  links, among other things.

- Pete Phillips helped during the development of the TAGS feature,
  and provided frequent feedback.

- Martin Pohlack provided the code snippet to bundle character
  insertion into bundles of 20 for undo.

- Ihor Radchenko helped with fixing bugs and improving the user
  experience regarding Org's speed.

- T.\nbsp{}V.\nbsp{}Raman reported bugs and suggested improvements.

- Matthias Rempe (Oelde) provided ideas, Windows support, and quality
  control.

- Paul Rivier provided the basic implementation of named footnotes.
  He also acted as mailing list moderator for some time.

- Kevin Rogers contributed code to access VM files on remote hosts.

- Frank Ruell solved the mystery of the =keymapp nil= bug, a conflict
  with =allout.el=.

- Jason Riedy generalized the send-receive mechanism for Orgtbl
  tables with extensive patches.

- Philip Rooke created the Org reference card, provided lots of
  feedback, developed and applied standards to the Org documentation.

- Christian Schlauer proposed angular brackets around links, among
  other things.

- Paul Sexton wrote =org-ctags.el=.

- Tom Shannon's =organizer-mode.el= inspired linking to VM/BBDB/Gnus.

- Ilya Shlyakhter proposed the Archive Sibling, line numbering in
  literal examples, and remote highlighting for referenced code lines.

- Stathis Sideris wrote the =ditaa.jar= ASCII to PNG converter that is
  now packaged into the [[https://git.sr.ht/~bzg/org-contrib][org-contrib]] repository.

- Daniel Sinder came up with the idea of internal archiving by locking
  subtrees.

- Dale Smith proposed link abbreviations.

- James TD Smith has contributed a large number of patches for
  useful tweaks and features.

- Adam Spiers asked for global linking commands, inspired the link
  extension system, added support for Mairix, and proposed the mapping
  API.

- Ulf Stegemann created the table to translate special symbols to
  HTML, LaTeX, UTF-8, Latin-1 and ASCII.

- Andy Stewart contributed code to =ol-w3m.el=, to copy
  HTML content with links transformation to Org syntax.

- David O'Toole wrote =org-publish.el= and drafted the
  manual chapter about publishing.

- Jambunathan\nbsp{}K.\nbsp{}contributed the ODT exporter.

- Sebastien Vauban reported many issues with LaTeX and Beamer export
  and enabled source code highlighting in Gnus.

- Stefan Vollmar organized a video-recorded talk at the
  Max-Planck-Institute for Neurology.  He also inspired the creation
  of a concept index for HTML export.

- Jürgen Vollmer contributed code generating the table of contents in
  HTML output.

- Samuel Wales has provided important feedback and bug reports.

- Chris Wallace provided a patch implementing the =QUOTE= block.

- David Wainberg suggested archiving, and improvements to the
  linking system.

- Carsten Wimmer suggested some changes and helped fix a bug in
  linking to Gnus.

- Roland Winkler requested additional key bindings to make Org work on
  a TTY.

- Piotr Zielinski wrote =org-mouse.el=, proposed agenda
  blocks and contributed various ideas and code snippets.

- Marco Wahl wrote =ol-eww.el=.

* GNU Free Documentation License
:PROPERTIES:
:APPENDIX: t
:DESCRIPTION: The license for this documentation.
:END:

#+texinfo: @include doclicense.texi

* Main Index
:PROPERTIES:
:INDEX:    cp
:DESCRIPTION: An index of Org's concepts and features.
:END:

* Key Index
:PROPERTIES:
:DESCRIPTION: Key bindings and where they are described.
:INDEX:    ky
:END:

* Command and Function Index
:PROPERTIES:
:DESCRIPTION: Command names and some internal functions.
:INDEX:    fn
:END:

* Variable Index
:PROPERTIES:
:DESCRIPTION: Variables mentioned in the manual.
:INDEX:    vr
:END:

This is not a complete index of variables and faces, only the ones
that are mentioned in the manual.  For a more complete list, use
{{{kbd(M-x org-customize)}}} and then click yourself through the tree.

* Copying
:PROPERTIES:
:copying:  t
:END:

This manual is for Org version {{{version}}}.

Copyright \copy 2004--2023 Free Software Foundation, Inc.

#+begin_quote
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with no
Invariant Sections, with the Front-Cover Texts being "A GNU Manual,"
and with the Back-Cover Texts as in (a) below.  A copy of the license
is included in the section entitled "GNU Free Documentation License."

(a) The FSF's Back-Cover Text is: "You have the freedom to copy and
modify this GNU manual."
#+end_quote

* Export Setup                                                          :noexport:

#+setupfile: org-setup.org

#+export_file_name: org.texi

#+texinfo_dir_category: Emacs editing modes
#+texinfo_dir_title: Org Mode: (org)
#+texinfo_dir_desc: Outline-based notes management and organizer

* Footnotes

[fn:1] See the variables ~org-special-ctrl-a/e~, ~org-special-ctrl-k~,
and ~org-ctrl-k-protect-subtree~ to configure special behavior of
{{{kbd(C-a)}}}, {{{kbd(C-e)}}}, and {{{kbd(C-k)}}} in headlines.  Note
also that clocking only works with headings indented less than 30
stars.

[fn:2] The indirect buffer contains the entire buffer, but is narrowed
to the current tree.  Editing the indirect buffer also changes the
original buffer, but without affecting visibility in that buffer.  For
more information about indirect buffers, see [[info:emacs#Indirect Buffers][GNU Emacs Manual]].

[fn:3] When using =*= as a bullet, lines must be indented so that they
are not interpreted as headlines.  Also, when you are hiding leading
stars to get a clean outline view, plain list items starting with
a star may be hard to distinguish from true headlines.  In short: even
though =*= is supported, it may be better to not use it for plain list
items.

[fn:4] You can also get =a.=, =A.=, =a)= and =A)= by configuring
~org-list-allow-alphabetical~.  To minimize confusion with normal
text, those are limited to one character only.  Beyond that limit,
bullets automatically become numbers.

[fn:5] If there's a checkbox in the item, the cookie must be put
/before/ the checkbox.  If you have activated alphabetical lists, you
can also use counters like =[@b]=.

[fn:6] Many desktops intercept {{{kbd(M-TAB)}}} to switch windows.
Use {{{kbd(C-M-i)}}} or {{{kbd(ESC TAB)}}} instead.

[fn:7] Org understands references typed by the user as =B4=, but it
does not use this syntax when offering a formula for editing.  You can
customize this behavior using the variable
~org-table-use-standard-references~.

[fn:8] The file =constants.el= can supply the values of constants in
two different unit systems, =SI= and =cgs=.  Which one is used depends
on the value of the variable ~constants-unit-system~.  You can use the
=STARTUP= options =constSI= and =constcgs= to set this value for the
current buffer.

[fn:9] The printf reformatting is limited in precision because the
value passed to it is converted into an "integer" or "double".  The
"integer" is limited in size by truncating the signed value to 32
bits.  The "double" is limited in precision to 64 bits overall which
leaves approximately 16 significant decimal digits.

[fn:10] Plain URIs are recognized only for a well-defined set of
schemes.  See [[*External Links]].  Unlike URI syntax, they cannot contain
parenthesis or white spaces, either.  URIs within angle brackets have
no such limitation.

[fn:11] To insert a link targeting a headline, in-buffer completion
can be used.  Just type a star followed by a few optional letters into
the buffer and press {{{kbd(M-TAB)}}}.  All headlines in the current
buffer are offered as completions.

[fn:12] The actual behavior of the search depends on the value of the
variable ~org-link-search-must-match-exact-headline~.  If its value is
~nil~, then a fuzzy text search is done.  If it is ~t~, then only the
exact headline is matched, ignoring spaces and statistic cookies.  If
the value is ~query-to-create~, then an exact headline is searched; if
it is not found, then the user is queried to create it.

[fn:13] Note that you do not have to use this command to insert
a link.  Links in Org are plain text, and you can type or paste them
straight into the buffer.  By using this command, the links are
automatically enclosed in double brackets, and you will be asked for
the optional descriptive text.

[fn:14] After insertion of a stored link, the link will be removed
from the list of stored links.  To keep it in the list for later use,
use a triple {{{kbd(C-u)}}} prefix argument to {{{kbd(C-c C-l)}}}, or
configure the option ~org-link-keep-stored-after-insertion~.

[fn:15] Check also the variable ~org-fast-tag-selection-include-todo~,
it allows you to change the TODO state through the tags interface (see
[[*Setting Tags]]), in case you like to mingle the two concepts.  Note
that this means you need to come up with unique keys across both sets
of keywords.

[fn:16] It is possible that Org mode records two timestamps when you
are using both ~org-log-done~ and state change logging.  However, it
never prompts for two notes: if you have configured both, the state
change recording note takes precedence and cancel the closing note.

[fn:17] With the exception of description lists.  But you can allow it
by modifying ~org-list-automatic-rules~ accordingly.

[fn:18] An age can be defined as a duration, using units defined in
~org-duration-units~, e.g., =3d 1h=.  If any value in the column is as
such, the summary is also expressed as a duration.

[fn:19] The Org date format is inspired by the standard ISO 8601
date/time format.  To use an alternative format, see [[*Custom time
format]].  The day name is optional when you type the date yourself.
However, any date inserted or modified by Org adds that day name, for
reading convenience.

[fn:20] When working with the standard diary expression functions, you
need to be very careful with the order of the arguments.  That order
depends evilly on the variable ~calendar-date-style~.  For example, to
specify a date December 1, 2005, the call might look like
=(diary-date 12 1 2005)= or =(diary-date 1 12 2005)= or =(diary-date
2005 12 1)=, depending on the settings.  This has been the source of
much confusion.  Org mode users can resort to special versions of
these functions, namely ~org-date~, ~org-anniversary~, ~org-cyclic, and
~org-block~.  These work just like the corresponding ~diary-~
functions, but with stable ISO order of arguments (year, month, day)
wherever applicable, independent of the value of
~calendar-date-style~.

[fn:21] See the variable ~org-read-date-prefer-future~.  You may set
that variable to the symbol ~time~ to even make a time before now
shift the date to tomorrow.

[fn:22] You can also use the calendar command {{{kbd(.)}}} to jump to
today's date, but if you are inserting an hour specification for your
timestamp, {{{kbd(.)}}} will then insert a dot after the hour.  By contrast,
{{{kbd(C-.)}}} will always jump to today's date.

[fn:23] It will still be listed on that date after it has been marked
as done.  If you do not like this, set the variable
~org-agenda-skip-scheduled-if-done~.

[fn:24] The =SCHEDULED= and =DEADLINE= dates are inserted on the line
right below the headline.  Do not put any text between this line and
the headline.

[fn:25] Org does not repeat inactive timestamps, however.  See
[[*Timestamps]].

[fn:26] You can change this using the option ~org-log-repeat~, or the
=STARTUP= options =logrepeat=, =lognoterepeat=, and =nologrepeat=.
With =lognoterepeat=, you will also be prompted for a note.

[fn:27] Clocking only works if all headings are indented with less
than 30 stars.  This is a hard-coded limitation of ~lmax~ in
~org-clock-sum~.

[fn:28] On computers using macOS, idleness is based on actual user
idleness, not just Emacs' idle time.  For X11, you can install a
utility program =x11idle.c=, available in the =org-contrib/=
repository, or install the xprintidle package and set it to the
variable ~org-clock-x11idle-program-name~ if you are running Debian,
to get the same general treatment of idleness.  On other systems, idle
time refers to Emacs idle time only.

[fn:29] Org used to offer four different targets for date/week tree
capture.  Now, Org automatically translates these to use
~file+olp+datetree~, applying the ~:time-prompt~ and ~:tree-type~
properties.  Please rewrite your date/week-tree targets using
~file+olp+datetree~ since the older targets are now deprecated.

[fn:30] A date tree is an outline structure with years on the highest
level, months or ISO weeks as sublevels and then dates on the lowest
level.

#+begin_example
,* 2022
,** 2022-10 October
,*** 2022-10-07 Friday
,*** 2022-10-08 Saturday
#+end_example

Tags are allowed in the tree structure.

[fn:31] This is always the other, not the user.  See the variable
~org-link-from-user-regexp~.

[fn:32] For backward compatibility, the universal prefix argument
{{{kbd(C-u)}}} causes all TODO entries to be listed before the agenda.
This feature is deprecated, use the dedicated TODO list, or a block
agenda instead (see [[*Block agenda]]).

[fn:33] Custom agenda commands can preset a filter by binding one of
the variables ~org-agenda-tag-filter-preset~,
~org-agenda-category-filter-preset~, ~org-agenda-effort-filter-preset~
or ~org-agenda-regexp-filter-preset~ as an option.  This filter is
then applied to the view and persists as a basic filter through
refreshes and more secondary filtering.  The filter is a global
property of the entire agenda view---in a block agenda, you should
only set this in the global options section, not in the section of an
individual block.

[fn:34] /Planned/ means here that these entries have some planning
information attached to them, like a time-stamp, a scheduled or
a deadline string.  See ~org-agenda-entry-types~ on how to set what
planning information is taken into account.

[fn:35] To create PDF output, the Ghostscript ps2pdf utility must be
installed on the system.  Selecting a PDF file also creates the
postscript file.

[fn:36] LaTeX is a macro system based on Donald\nbsp{}E.\nbsp{}Knuth's TeX
system.  Many of the features described here as "LaTeX" are really
from TeX, but for simplicity I am blurring this distinction.

[fn:37] When MathJax is used, only the environments recognized by
MathJax are processed.  When dvipng, dvisvgm, or ImageMagick suite is
used to create images, any LaTeX environment is handled.

[fn:38] These are respectively available at
[[https://sourceforge.net/projects/dvipng/]], [[http://dvisvgm.bplaced.net/]]
and from the ImageMagick suite.  Choose the converter by setting the
variable ~org-preview-latex-default-process~ accordingly.

[fn:39] This works automatically for the HTML backend (it requires
version 1.34 of the =htmlize.el= package, which you need to install).
Fontified code chunks in LaTeX can be achieved using either the
[[https://www.ctan.org/pkg/listings][listings]] LaTeX package, [[https://www.ctan.org/pkg/minted][minted]] LaTeX package, or by using
[[https://elpa.gnu.org/packages/engrave-faces.html][engrave-faces]] .  Refer to ~org-latex-src-block-backend~ for details.

[fn:40] Source code in code blocks may also be evaluated either
interactively or on export.  See [[*Working with Source Code]] for more
information on evaluating code blocks.

[fn:41] For export to LaTeX format---or LaTeX-related formats such as
Beamer---, the =org-latex-package-alist= variable needs further
configuration.  See [[LaTeX specific export settings]].

[fn:42] At the moment, some export back-ends do not obey this
specification.  For example, LaTeX export excludes every unnumbered
headline from the table of contents.

[fn:43] Note that ~org-link-search-must-match-exact-headline~ is
locally bound to non-~nil~.  Therefore, ~org-link-search~ only matches
headlines and named elements.

[fn:44] Since commas separate the arguments, commas within arguments
have to be escaped with the backslash character.  So only those
backslash characters before a comma need escaping with another
backslash character.

[fn:45] If =BEAMER_ENV= is set, Org export adds =B_environment= tag
to make it visible.  The tag serves as a visual aid and has no
semantic relevance.

[fn:46] Please note that exported formulas are part of an HTML
document, and that signs such as =<=, =>=, or =&= have special
meanings.  See [[https://docs.mathjax.org/en/latest/input/tex/html.html#tex-and-latex-in-html-documents][MathJax TeX and LaTeX in HTML documents]].

[fn:47] This does not allow setting different bibliography compilers
for different files.  However, "smart" LaTeX compilation systems, such
as latexmk, can select the correct bibliography compiler.

[fn:48] Actually, the constructs =call_<name>()= and =src_<lang>{}=
are not evaluated when they appear in a keyword (see [[*Summary of
In-Buffer Settings]]).

[fn:49] Org Indent mode also sets ~wrap-prefix~ correctly for
indenting and wrapping long lines of headlines or text.  This minor
mode also handles Visual Line mode and directly applied settings
through ~word-wrap~.

[fn:50] This works, but requires extra effort.  Org Indent mode is
more convenient for most applications.

[fn:51] For a server to host files, consider using a WebDAV server,
such as [[https://nextcloud.com][Nextcloud]].  Additional help is at this [[https://orgmode.org/worg/org-faq.html#mobileorg_webdav][FAQ entry]].

[fn:52] While creating the agendas, Org mode forces =ID= properties
on all referenced entries, so that these entries can be uniquely
identified if Org Mobile flags them for further action.  To avoid
setting properties configure the variable
~org-mobile-force-id-on-agenda-items~ to ~nil~.  Org mode then relies
on outline paths, assuming they are unique.

[fn:53] By default this works only for LaTeX, HTML, and Texinfo.
Configure the variable ~orgtbl-radio-table-templates~ to install
templates for other modes.

[fn:54] If the =TBLFM= keyword contains an odd number of dollar
characters, this may cause problems with Font Lock in LaTeX mode.  As
shown in the example you can fix this by adding an extra line inside
the =comment= environment that is used to balance the dollar
expressions.  If you are using AUCTeX with the font-latex library,
a much better solution is to add the =comment= environment to the
variable ~LaTeX-verbatim-environments~.
