#+title:                 denote: Simple notes with an efficient file-naming scheme
#+author:                Protesilaos Stavrou
#+email:                 info@protesilaos.com
#+language:              en
#+options:               ':t toc:nil author:t email:t num:t
#+startup:               content
#+macro:                 stable-version 1.2.0
#+macro:                 release-date 2022-12-16
#+macro:                 development-version 1.3.0-dev
#+export_file_name:      denote.texi
#+texinfo_filename:      denote.info
#+texinfo_dir_category:  Emacs misc features
#+texinfo_dir_title:     Denote: (denote)
#+texinfo_dir_desc:      Simple notes with an efficient file-naming scheme
#+texinfo_header:        @set MAINTAINERSITE @uref{https://protesilaos.com,maintainer webpage}
#+texinfo_header:        @set MAINTAINER Protesilaos Stavrou
#+texinfo_header:        @set MAINTAINEREMAIL @email{info@protesilaos.com}
#+texinfo_header:        @set MAINTAINERCONTACT @uref{mailto:info@protesilaos.com,contact the maintainer}

#+texinfo: @insertcopying

This manual, written by Protesilaos Stavrou, describes the customization
options for the Emacs package called =denote= (or =denote.el=), and
provides every other piece of information pertinent to it.

The documentation furnished herein corresponds to stable version
{{{stable-version}}}, released on {{{release-date}}}.  Any reference to
a newer feature which does not yet form part of the latest tagged
commit, is explicitly marked as such.

Current development target is {{{development-version}}}.

+ Package name (GNU ELPA): =denote=
+ Official manual: <https://protesilaos.com/emacs/denote>
+ Change log: <https://protesilaos.com/emacs/denote-changelog>
+ Git repo on SourceHut: <https://git.sr.ht/~protesilaos/denote>
  - Mirrors:
    + GitHub: <https://github.com/protesilaos/denote>
    + GitLab: <https://gitlab.com/protesilaos/denote>
+ Mailing list: <https://lists.sr.ht/~protesilaos/denote>
+ Backronyms: Denote Everything Neatly; Omit The Excesses.  Don't Ever
  Note Only The Epiphenomenal.

If you are viewing the README.org version of this file, please note that
the GNU ELPA machinery automatically generates an Info manual out of it.

#+toc: headlines 8 insert TOC here, with eight headline levels

* COPYING
:PROPERTIES:
:COPYING: t
:CUSTOM_ID: h:40b18bb2-4dc1-4202-bd0b-6fab535b2a0f
:END:

Copyright (C) 2022  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

* Overview
:PROPERTIES:
:CUSTOM_ID: h:a09b70a2-ae0b-4855-ac14-1dddfc8e3241
:END:

Denote aims to be a simple-to-use, focused-in-scope, and effective
note-taking tool for Emacs.  It is based on the following core design
principles:

+ Predictability :: File names must follow a consistent and descriptive
  naming convention ([[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file-naming scheme]]).  The file name alone
  should offer a clear indication of what the contents are, without
  reference to any other metadatum.  This convention is not specific to
  note-taking, as it is pertinent to any form of file that is part of
  the user's long-term storage ([[#h:532e8e2a-9b7d-41c0-8f4b-3c5cbb7d4dca][Renaming files]]).

+ Composability :: Be a good Emacs citizen, by integrating with other
  packages or built-in functionality instead of re-inventing functions
  such as for filtering or greping.  The author of Denote (Protesilaos,
  aka "Prot") writes ordinary notes in plain text (=.txt=), switching on
  demand to an Org file only when its expanded set of functionality is
  required for the task at hand ([[#h:17896c8c-d97a-4faa-abf6-31df99746ca6][Points of entry]]).

+ Portability :: Notes are plain text and should remain portable.  The
  way Denote writes file names, the front matter it includes in the
  note's header, and the links it establishes must all be adequately
  usable with standard Unix tools.  No need for a database or some
  specialised software.  As Denote develops and this manual is fully
  fleshed out, there will be concrete examples on how to do the
  Denote-equivalent on the command-line.

+ Flexibility :: Do not assume the user's preference for a note-taking
  methodology.  Denote is conceptually similar to the Zettelkasten
  Method, which you can learn more about in this detailed introduction:
  <https://zettelkasten.de/introduction/>.  Notes are atomic (one file
  per note) and have a unique identifier.  However, Denote does not
  enforce a particular methodology for knowledge management, such as a
  restricted vocabulary or mutually exclusive sets of keywords.  Denote
  also does not check if the user writes thematically atomic notes.  It
  is up to the user to apply the requisite rigor and/or creativity in
  pursuit of their preferred workflow ([[#h:6060a7e6-f179-4d42-a9de-a9968aaebecc][Writing metanotes]]).

+ Hackability :: Denote's code base consists of small and reusable
  functions.  They all have documentation strings.  The idea is to make
  it easier for users of varying levels of expertise to understand what
  is going on and make surgical interventions where necessary (e.g. to
  tweak some formatting).  In this manual, we provide concrete examples
  on such user-level configurations ([[#h:4a6d92dd-19eb-4fcc-a7b5-05ce04da3a92][Keep a journal or diary]]).

Now the important part...  "Denote" is the familiar word, though it also
is a play on the "note" concept.  Plus, we can come up with acronyms,
recursive or otherwise, of increasingly dubious utility like:

+ Don't Ever Note Only The Epiphenomenal
+ Denote Everything Neatly; Omit The Excesses

But we'll let you get back to work.  Don't Eschew or Neglect your
Obligations, Tasks, and Engagements.

* Points of entry
:PROPERTIES:
:CUSTOM_ID: h:17896c8c-d97a-4faa-abf6-31df99746ca6
:END:

#+findex: denote
#+findex: denote-type
#+findex: denote-org-capture
#+findex: denote-date
#+findex: denote-subdirectory
#+findex: denote-template
There are five ways to write a note with Denote: invoke the ~denote~,
~denote-type~, ~denote-date~, ~denote-subdirectory~, ~denote-template~
commands, or leverage the ~org-capture-templates~ by setting up a
template which calls the function ~denote-org-capture~.  We explain all
of those in the subsequent sections.

** Standard note creation
:PROPERTIES:
:CUSTOM_ID: h:6a92a8b5-d766-42cc-8e5b-8dc255466a23
:END:

The ~denote~ command will prompt for a title.  If a region is active,
the text of the region becomes the default at the minibuffer prompt
(meaning that typing =RET= without any input will use the default
value).  Once the title is supplied, the ~denote~ command will then ask
for keywords.  The resulting note will have a file name as already
explained: [[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file naming scheme]]

The file type of the new note is determined by the user option
~denote-file-type~ ([[#h:13218826-56a5-482a-9b91-5b6de4f14261][Front matter]]).

#+vindex: denote-known-keywords
#+vindex: denote-infer-keywords
The keywords' prompt supports minibuffer completion.  Available
candidates are those defined in the user option ~denote-known-keywords~.
More candidates can be inferred from the names of existing notes, by
setting ~denote-infer-keywords~ to non-nil (which is the case by
default).

#+vindex: denote-sort-keywords
Multiple keywords can be inserted by separating them with a comma (or
whatever the value of the ~crm-separator~ is---which should be a comma).
When the user option ~denote-sort-keywords~ is non-nil (the default),
keywords are sorted alphabetically (technically, the sorting is done
with ~string-lessp~).

The interactive behaviour of the ~denote~ command is influenced by the
user option ~denote-prompts~ ([[#h:f9204f1f-fcee-49b1-8081-16a08a338099][The denote-prompts option]]).

The ~denote~ command can also be called from Lisp.  Read its doc string
for the technicalities.

#+findex: denote-create-note
In the interest of discoverability, ~denote~ is also available under the
alias ~denote-create-note~.

*** The ~denote-prompts~ option
:PROPERTIES:
:CUSTOM_ID: h:f9204f1f-fcee-49b1-8081-16a08a338099
:END:

#+vindex: denote-prompts
The user option ~denote-prompts~ determines how the ~denote~ command
will behave interactively ([[#h:6a92a8b5-d766-42cc-8e5b-8dc255466a23][Standard note creation]]).

The value is a list of symbols, which includes any of the following:

- =title=: Prompt for the title of the new note.

- =keywords=: Prompts with completion for the keywords of the new note.
  Available candidates are those specified in the user option
  ~denote-known-keywords~.  If the user option ~denote-infer-keywords~
  is non-nil, keywords in existing note file names are included in the
  list of candidates.  The =keywords= prompt uses
  ~completing-read-multiple~, meaning that it can accept multiple
  keywords separated by a comma (or whatever the value of ~crm-sepator~
  is).

- =file-type=: Prompts with completion for the file type of the new
  note.  Available candidates are those specified in the user option
  ~denote-file-type~.  Without this prompt, ~denote~ uses the value of
  ~denote-file-type~.

- =subdirectory=: Prompts with completion for a subdirectory in which to
  create the note.  Available candidates are the value of the user
  option ~denote-directory~ and all of its subdirectories.  Any
  subdirectory must already exist: Denote will not create it.

- =date=: Prompts for the date of the new note.  It will expect an input
  like 2022-06-16 or a date plus time: 2022-06-16 14:30.  Without the
  =date= prompt, the ~denote~ command uses the ~current-time~.

  [[#h:e7ef08d6-af1b-4ab3-bb00-494a653e6d63][The denote-date-prompt-use-org-read-date option]].

- =template=: Prompts for a KEY among the ~denote-templates~.  The value
  of that KEY is used to populate the new note with content, which is
  added after the front matter ([[#h:f635a490-d29e-4608-9372-7bd13b34d56c][The denote-templates option]]).

The prompts occur in the given order.

If the value of this user option is nil, no prompts are used.  The
resulting file name will consist of an identifier (i.e. the date and
time) and a supported file type extension (per ~denote-file-type~).

Recall that Denote's standard file-naming scheme is defined as follows
([[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file-naming scheme]]):

: DATE--TITLE__KEYWORDS.EXT

If either or both of the =title= and =keywords= prompts are not
included in the value of this variable, file names will be any of
those permutations:

: DATE.EXT
: DATE--TITLE.EXT
: DATE__KEYWORDS.EXT

When in doubt, always include the =title= and =keywords= prompts.

Finally, this user option only affects the interactive use of the
~denote~ command (advanced users can call it from Lisp).  For ad-hoc
interactive actions that do not change the default behaviour of the
~denote~ command, users can invoke these convenience commands:
~denote-type~, ~denote-subdirectory~, ~denote-date~.  They are described
in the subsequent section ([[#h:887bdced-9686-4e80-906f-789e407f2e8f][Convenience commands for note creation]]).

*** The ~denote-templates~ option
:PROPERTIES:
:CUSTOM_ID: h:f635a490-d29e-4608-9372-7bd13b34d56c
:END:

#+vindex: denote-templates
The user option ~denote-templates~ is an alist of content templates for
new notes.  A template is arbitrary text that Denote will add to a newly
created note right below the front matter.

Templates are expressed as a =(KEY . STRING)= association.

- The =KEY= is the name which identifies the template.  It is an
  arbitrary symbol, such as =report=, =memo=, =statement=.

- The =STRING= is ordinary text that Denote will insert as-is.  It can
  contain newline characters to add spacing.  Below we show some
  concrete examples.

The user can choose a template either by invoking the command
~denote-template~ or by changing the user option ~denote-prompts~ to
always prompt for a template when calling the ~denote~ command.

[[#h:f9204f1f-fcee-49b1-8081-16a08a338099][The denote-prompts option]].

[[#h:887bdced-9686-4e80-906f-789e407f2e8f][Convenience commands for note creation]].

Templates can be written directly as one large string.  For example (the
=\n= character is read as a newline):

#+begin_src emacs-lisp
(setq denote-templates
      '((report . "* Some heading\n\n* Another heading")
        (memo . "* Some heading

,* Another heading

")))
#+end_src

Long strings may be easier to type but interpret indentation literally.
Also, they do not scale well.  A better way is to use some Elisp code to
construct the string.  This would typically be the ~concat~ function,
which joins multiple strings into one.  The following is the same as the
previous example:

#+begin_src emacs-lisp
(setq denote-templates
      `((report . "* Some heading\n\n* Another heading")
        (memo . ,(concat "* Some heading"
                         "\n\n"
                         "* Another heading"
                         "\n\n"))))
#+end_src

Notice that to evaluate a function inside of an alist we use the
backtick to quote the alist (NOT the straight quote) and then prepend a
comma to the expression that should be evaluated.  The ~concat~ form
here is not sensitive to indentation, so it is easier to adjust for
legibility.

DEV NOTE: We do not provide more examples at this point, though feel
welcome to ask for help if the information provided herein is not
sufficient.  We shall expand the manual accordingly.

*** Convenience commands for note creation
:PROPERTIES:
:CUSTOM_ID: h:887bdced-9686-4e80-906f-789e407f2e8f
:END:

Sometimes the user needs to create a note that has different
requirements from those of ~denote~ ([[#h:6a92a8b5-d766-42cc-8e5b-8dc255466a23][Standard note creation]]).  While
this can be achieved globally by changing the ~denote-prompts~ user
option, there are cases where an ad-hoc method is the appropriate one
([[#h:f9204f1f-fcee-49b1-8081-16a08a338099][The denote-prompts option]]).

To this end, Denote provides the following convenience interactive
commands for note creation:

+ Create note by specifying file type :: The ~denote-type~ command
  creates a note while prompting for a file type.

  This is the equivalent to calling ~denote~ when ~denote-prompts~ is
  set to ='(file-type title keywords)=.  In practical terms, this lets
  you produce, say, a note in Markdown even though you normally write in
  Org ([[#h:6a92a8b5-d766-42cc-8e5b-8dc255466a23][Standard note creation]]).

  #+findex: denote-create-note-using-type
  The ~denote-create-note-using-type~ is an alias of ~denote-type~.

+ Create note using a date :: Normally, Denote reads the current date
  and time to construct the unique identifier of a newly created note
  ([[#h:6a92a8b5-d766-42cc-8e5b-8dc255466a23][Standard note creation]]).  Sometimes, however, the user needs to set
  an explicit date+time value.

  This is where the ~denote-date~ command comes in.  It creates a note
  while prompting for a date.  The date can be in YEAR-MONTH-DAY
  notation like =2022-06-30= or that plus the time: =2022-06-16 14:30=.

  [[#h:e7ef08d6-af1b-4ab3-bb00-494a653e6d63][The denote-date-prompt-use-org-read-date option]].

  This is the equivalent to calling ~denote~ when ~denote-prompts~ is
  set to ='(date title keywords)=.

  #+findex: denote-create-note-using-date
  The ~denote-create-note-using-date~ is an alias of ~denote-date~.

+ Create note in a specific directory :: The ~denote-subdirectory~
  command creates a note while prompting for a subdirectory.  Available
  candidates include the value of the variable ~denote-directory~ and
  any subdirectory thereof (Denote does not create subdirectories).

  This is equivalent to calling ~denote~ when ~denote-prompts~ is set to
  ='(subdirectory title keywords)=.

  #+findex: denote-create-note-in-subdirectory
  The ~denote-create-note-in-subdirectory~ is a more descriptive alias
  of ~denote-subdirectory~.

+ Create note and add a template :: The ~denote-template~ command
  creates a new note and inserts the specified template below the front
  matter ([[#h:f635a490-d29e-4608-9372-7bd13b34d56c][The denote-templates option]]).  Available candidates for
  templates are specified in the user option ~denote-templates~.

  This is equivalent to calling ~denote~ when ~denote-prompts~ is
  set to ='(template title keywords)=.

  #+findex: denote-create-note-with-template
  The ~denote-create-note-with-template~ is an alias of the command
  ~denote-template~, meant to help with discoverability.

**** Write your own convenience commands
:PROPERTIES:
:CUSTOM_ID: h:11946562-7eb0-4925-a3b5-92d75f1f5895
:END:

The convenience commands we provide only cover some basic use-cases
([[#h:887bdced-9686-4e80-906f-789e407f2e8f][Convenience commands for note creation]]).  The user may require
combinations that are not covered, such as to prompt for a template and
for a subdirectory, instead of only one of the two.  To this end, we
show how to follow the code we use in Denote to write your own variants
of those commands.

First let's take a look at the definition of one of those commands.
They all look the same, but we use ~denote-subdirectory~ for this
example:

#+begin_src emacs-lisp
(defun denote-subdirectory ()
  "Create note while prompting for a subdirectory.

Available candidates include the value of the variable
`denote-directory' and any subdirectory thereof.

This is equivalent to calling `denote' when `denote-prompts' is
set to '(subdirectory title keywords)."
  (declare (interactive-only t))
  (interactive)
  (let ((denote-prompts '(subdirectory title keywords)))
    (call-interactively #'denote)))
#+end_src

The hyphenated word after ~defun~ is the name of the function.  It has
to be unique.  Then we have the documentation string (or "doc string")
which is for the user's convenience.

This function is ~interactive~, meaning that it can be called via =M-x=
or be assigned to a key binding.  Then we have the local binding of the
~denote-prompts~ to the desired combination ("local" means specific to
this function without affecting other contexts).  Lastly, it calls the
standard ~denote~ command interactively, so it uses all the prompts in
their specified order.

Now let's say we want to have a command that (i) asks for a template and
(ii) for a subdirectory ([[#h:f635a490-d29e-4608-9372-7bd13b34d56c][The denote-templates option]]).  All we need to
do is tweak the ~let~ bound value of ~denote-prompts~ and give our
command a unique name:

#+begin_src emacs-lisp
;; Like `denote-subdirectory' but also ask for a template
(defun denote-subdirectory-with-template ()
  "Create note while also prompting for a template and subdirectory.

This is equivalent to calling `denote' when `denote-prompts' is
set to '(template subdirectory title keywords)."
  (declare (interactive-only t))
  (interactive)
  (let ((denote-prompts '(template subdirectory title keywords)))
    (call-interactively #'denote)))
#+end_src

The tweaks to ~denote-prompts~ determine how the command will behave
([[#h:f9204f1f-fcee-49b1-8081-16a08a338099][The denote-prompts option]]).  Use this paradigm to write your own
variants which you can then assign to keys or invoke with =M-x=.

*** The ~denote-date-prompt-use-org-read-date~ option
:PROPERTIES:
:CUSTOM_ID: h:e7ef08d6-af1b-4ab3-bb00-494a653e6d63
:END:

By default, Denote uses its own simple prompt for date or date+time
input ([[#h:f9204f1f-fcee-49b1-8081-16a08a338099][The denote-prompts option]]).  This is done when the
~denote-prompts~ option includes a =date= symbol and/or when the user
invokes the ~denote-date~ command.

#+vindex: denote-date-prompt-use-org-read-date
Users who want to benefit from the more advanced date selection method
that is common in interactions with Org mode, can set the user option
~denote-date-prompt-use-org-read-date~ to a non-nil value.

*** Add or remove keywords interactively
:PROPERTIES:
:CUSTOM_ID: h:ad4dde4a-8e88-470a-97ae-e7b9d4b41fb4
:END:

#+findex: denote-keywords-add
#+findex: denote-keywords-remove
The commands ~denote-keywords-add~ and ~denote-keywords-remove~
streamline the process of interactively updating a file's keywords in
the front matter and renaming it accordingly.

The ~denote-keywords-add~ asks for keywords using the familiar
minibuffer prompt ([[#h:6a92a8b5-d766-42cc-8e5b-8dc255466a23][Standard note creation]]).  It then renames the file
([[#h:3ab08ff4-81fa-4d24-99cb-79f97c13a373][Rename a single file based on its front matter]]).

Similarly, the ~denote-keywords-remove~ removes one or more keywords
from the list of existing keywords and then renames the file
accordingly.

** Create note using Org capture
:PROPERTIES:
:CUSTOM_ID: h:656c70cd-cf9a-4471-a0b5-4f0aaf60f881
:END:

For integration with ~org-capture~, the user must first add the relevant
template.  Such as:

#+begin_src emacs-lisp
(with-eval-after-load 'org-capture
  (add-to-list 'org-capture-templates
               '("n" "New note (with Denote)" plain
                 (file denote-last-path)
                 #'denote-org-capture
                 :no-save t
                 :immediate-finish nil
                 :kill-buffer t
                 :jump-to-captured t)))
#+end_src

[ In the future, we might develop Denote in ways which do not require such
  manual intervention.  More user feedback is required to identify the
  relevant workflows. ]

Once the template is added, it is accessed from the specified key.  If,
for instance, ~org-capture~ is bound to =C-c c=, then the note creation
is initiated with =C-c c n=, per the above snippet.  After that, the
process is the same as with invoking ~denote~ directly, namely: a prompt
for a title followed by a prompt for keywords ([[#h:6a92a8b5-d766-42cc-8e5b-8dc255466a23][Standard note creation]]).

#+vindex: denote-org-capture-specifiers
Users may prefer to leverage ~org-capture~ in order to extend file
creation with the specifiers described in the ~org-capture-templates~
documentation (such as to capture the active region and/or create a
hyperlink pointing to the given context).

IMPORTANT.  Due to the particular file-naming scheme of Denote, which is
derived dynamically, such specifiers or other arbitrary text cannot be
written directly in the template.  Instead, they have to be assigned to
the user option ~denote-org-capture-specifiers~, which is interpreted by
the function ~denote-org-capture~.  Example with our default value:

#+begin_src emacs-lisp
(setq denote-org-capture-specifiers "%l\n%i\n%?")
#+end_src

Note that ~denote-org-capture~ ignores the ~denote-file-type~: it always
sets the Org file extension for the created note to ensure that the
capture process works as intended, especially for the desired output of
the ~denote-org-capture-specifiers~.

** Maintain separate directory silos for notes
:PROPERTIES:
:CUSTOM_ID: h:15719799-a5ff-4e9a-9f10-4ca03ef8f6c5
:END:
#+cindex: Note silos

The user option ~denote-directory~ accepts a value that represents the
path to a directory, such as =~/Documents/notes=.  Normally, the user
will have one place where they store all their notes, in which case this
arrangement shall suffice.

There is, however, the possibility to maintain separate directories of
notes.  By "separate", we mean that they do not communicate with each
other: no linking between them, no common keywords, nothing.  Think of
the scenario where one set of notes is for private use and another is
for an employer.  We call these separate directories "silos".

To create silos, the user must specify a local variable at the root of
the desired directory.  This is done by creating a =.dir-locals.el=
file, with the following contents:

#+begin_src emacs-lisp
;;; Directory Local Variables.  For more information evaluate:
;;;
;;;     (info "(emacs) Directory Variables")

((nil . ((denote-directory . default-directory))))
#+end_src

When inside the directory that contains this =.dir-locals.el= file, all
Denote commands/functions for note creation, linking, the inference of
available keywords, et cetera will use the silo as their point of
reference.  They will not read the global value of ~denote-directory~.
The global value of ~denote-directory~ is read everywhere else except
the silos.

In concrete terms, this is a representation of the directory structures
(notice the =.dir-locals.el= file is needed only for the silos):

#+begin_example
;; This is the global value of 'denote-directory' (no need for a .dir-locals.el)
~/Documents/notes
|-- 20210303T120534--this-is-a-test__journal_philosophy.txt
|-- 20220303T120534--another-sample__journal_testing.md
`-- 20220620T181255--the-third-test__keyword.org

;; A silo with notes for the employer
~/different/path/to/notes-for-employer
|-- .dir-locals.el
|-- 20210303T120534--this-is-a-test__conference.txt
|-- 20220303T120534--another-sample__meeting.md
`-- 20220620T181255--the-third-test__keyword.org

;; Another silo with notes for my volunteering
~/different/path/to/notes-for-volunteering
|-- .dir-locals.el
|-- 20210303T120534--this-is-a-test__activism.txt
|-- 20220303T120534--another-sample__teambuilding.md
`-- 20220620T181255--the-third-test__keyword.org
#+end_example

It is possible to configure other user options of Denote to have a
silo-specific value.  For example, this one changes the
~denote-known-keywords~ only for this particular silo:

#+begin_src emacs-lisp
;;; Directory Local Variables.  For more information evaluate:
;;;
;;;     (info "(emacs) Directory Variables")

((nil . ((denote-directory . default-directory)
         (denote-known-keywords . ("food" "drink")))))
#+end_src

This one is like the above, but also disables ~denote-infer-keywords~:

#+begin_src emacs-lisp
;;; Directory Local Variables.  For more information evaluate:
;;;
;;;     (info "(emacs) Directory Variables")

((nil . ((denote-directory . default-directory)
         (denote-known-keywords . ("food" "drink"))
         (denote-infer-keywords . nil))))
#+end_src

To expand the list of local variables to, say, cover specific major
modes, we can do something like this:

#+begin_src emacs-lisp
;;; Directory Local Variables.  For more information evaluate:
;;;
;;;     (info "(emacs) Directory Variables")

((nil . ((denote-directory . default-directory)
         (denote-known-keywords . ("food" "drink"))
         (denote-infer-keywords . nil)))
 (org-mode . ((org-hide-emphasis-markers . t)
              (org-hide-macro-markers . t)
              (org-hide-leading-stars . t))))
#+end_src

As not all user options have a "safe" local value, Emacs will ask the
user to confirm their choice and to store it in the Custom code
snippet that is normally appended to init file (or added to the file
specified by the user option ~custom-file~).

Finally, it is possible to have a =.dir-locals.el= for subdirectories
of any ~denote-directory~.  Perhaps to specify a different set of
known keywords, while not making the subdirectory a silo in its own
right.  We shall not expand on such an example, as we trust the user
to experiment with the best setup for their workflow.

Feel welcome to ask for help if the information provided herein is not
sufficient.  The manual shall be expanded accordingly.

** Exclude certain directories from all operations
:PROPERTIES:
:CUSTOM_ID: h:8458f716-f9c2-4888-824b-2bf01cc5850a
:END:

#+vindex: denote-excluded-directories-regexp
The user option ~denote-excluded-directories-regexp~ instructs all
Denote functions that read or check file/directory names to omit
directories that match the given regular expression.  The regexp needs
to match only the name of the directory, not its full path.

Affected operations include file prompts and functions that return the
available files in the value of the user option ~denote-directory~
([[#h:15719799-a5ff-4e9a-9f10-4ca03ef8f6c5][Maintain separate directory silos for notes]]).

File prompts are used by several commands, such as ~denote-link~ and
~denote-subdirectory~.

Functions that check for files include ~denote-directory-files~ and
~denote-directory-subdirectories~.

The match is performed with ~string-match-p~.

[[#h:c916d8c5-540a-409f-b780-6ccbd90e088e][For developers or advanced users]].

** Exclude certain keywords from being inferred
:PROPERTIES:
:CUSTOM_ID: h:69e518ee-ed43-40ab-a5f4-c780a23e5358
:END:

#+vindex: denote-excluded-keywords-regexp
The user option ~denote-excluded-keywords-regexp~ omits keywords that
match a regular expression from the list of inferred keywords.

Keywords are inferred from file names and provided at relevant prompts
as completion candidates when the user option ~denote-infer-keywords~
is non-nil.

The match is performed with ~string-match-p~.

* Renaming files
:PROPERTIES:
:CUSTOM_ID: h:532e8e2a-9b7d-41c0-8f4b-3c5cbb7d4dca
:END:

Denote provides commands to rename files and update their front matter
where relevant.  For Denote to work, only the file name needs to be in
order, by following our naming conventions ([[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file-naming scheme]]).
The linking mechanism, in particular, needs just the identifier in the
file name ([[#h:fc913d54-26c8-4c41-be86-999839e8ad31][Linking notes]]).

We write front matter in notes for the user's convenience and for other
tools to make use of that information (e.g. Org's export mechanism).
The renaming mechanism takes care to keep this data in sync with the
file name, when the user performs a change.

Renaming is useful for managing existing files created with Denote, but
also for converting older text files to Denote notes.

Lastly, Denote's file-naming scheme is not specific to notes or text
files: it is useful for all sorts of items, such as multimedia and PDFs
that form part of the user's longer-term storage.  While Denote does not
manage such files (e.g. doesn't create links to them), it already has
all the mechanisms to facilitate the task of renaming them.

** Rename a single file
:PROPERTIES:
:CUSTOM_ID: h:7cc9e000-806a-48da-945c-711bbc7426b0
:END:

#+findex: denote-rename-file
The ~denote-rename-file~ command renames a file and updates existing
front matter if appropriate.

If in Dired, the =FILE= to be renamed is the one at point, else the
command prompts with minibuffer completion for a target file.

If =FILE= has a Denote-compliant identifier, retain it while updating
the =TITLE= and =KEYWORDS= fields of the file name.  Else create an
identifier based on the following conditions:

- If =FILE= does not have an identifier and optional =DATE= is non-nil
  (such as with a prefix argument), invoke the function
  ~denote-prompt-for-date-return-id~.  It prompts for a date and uses
  it to derive the identifier.

- If =FILE= does not have an identifier and optional =DATE= is nil
  (this is the case without a prefix argument), use the file
  attributes to determine the last modified date and format it as an
  identifier.

- As a fallback, derive an identifier from the current time.

The default =TITLE= is retrieved from a line starting with a title field
in the file's contents, depending on the given file type ([[#h:13218826-56a5-482a-9b91-5b6de4f14261][Front matter]]).
Else, the file name is used as a default value at the minibuffer prompt.

As a final step after the =FILE=, =TITLE=, and =KEYWORDS= prompts, ask
for confirmation, showing the difference between old and new file names.
For example:

#+begin_example
Rename sample.txt to 20220612T052900--my-sample-title__testing.txt? (y or n)
#+end_example

The file type extension (e.g. =.txt=) is read from the underlying file
and is preserved through the renaming process.  Files that have no
extension are simply left without one.

Renaming only occurs relative to the current directory.  Files are not
moved between directories.

If the =FILE= has Denote-style front matter for the =TITLE= and
=KEYWORDS=, this command asks to rewrite their values in order to
reflect the new input (this step always requires confirmation and the
underlying buffer is not saved, so consider invoking
~diff-buffer-with-file~ to double-check the effect).  The rewrite of the
=FILE= and =KEYWORDS= in the front matter should not affect the rest of
the block.

If the file doesn't have front matter but is among the supported file
types (per ~denote-file-type~), the ~denote-rename-file~ command adds
front matter at the top of it and leaves the buffer unsaved for further
inspection.

This command is intended to (i) rename existing Denote notes while
updating their title and keywords in the front matter, (ii) convert
existing supported file types to Denote notes, and (ii) rename non-note
files (e.g. PDF) that can benefit from Denote's file-naming scheme.  The
latter is a convenience we provide, since we already have all the
requisite mechanisms in place (though Denote does not---and will
not---manage such files).

** Rename multiple files at once
:PROPERTIES:
:CUSTOM_ID: h:1b6b2c78-42f0-45b8-9ef0-6de21a8b2cde
:END:

#+findex: denote-dired-rename-marked-files
The ~denote-dired-rename-marked-files~ command renames marked files in
Dired to conform with our file-naming scheme.  The operation does the
following:

- the file's existing file name is retained and becomes the =TITLE=
  field, per Denote's file-naming scheme;

- the =TITLE= is sluggified and downcased, per our conventions;

- an identifier is prepended to the =TITLE=;

- the file's extension is retained;

- a prompt is asked once for the =KEYWORDS= field and the input is
  applied to all file names;

- if the file is recognized as a Denote note, this command adds or
  rewrites front matter to include the new keywords.  A confirmation to
  carry out this step is performed once at the outset.  Note that the
  affected buffers are not saved.  The user can thus check them to
  confirm that the new front matter does not cause any problems
  (e.g. with the command ~diff-buffer-with-file~).  Multiple buffers can
  be saved with ~save-some-buffers~ (read its doc string).  The addition
  of front matter takes place only if the given file has the appropriate
  file type extension (per the user option ~denote-file-type~).

** Rename a single file based on its front matter
:PROPERTIES:
:CUSTOM_ID: h:3ab08ff4-81fa-4d24-99cb-79f97c13a373
:END:

#+findex: denote-rename-file-using-front-matter
In the previous section, we covered the more general mechanism of the
command ~denote-rename-file~ ([[#h:7cc9e000-806a-48da-945c-711bbc7426b0][Rename a single file]]).  There is also a
way to have the same outcome by making Denote read the data in the
current file's front matter and use it to construct/update the file
name.  The command for this is ~denote-rename-file-using-front-matter~.
It is only relevant for files that (i) are among the supported file
types, per ~denote-file-type~, and (ii) have the requisite front matter
in place.

Suppose you have an =.org= file with this front matter ([[#h:13218826-56a5-482a-9b91-5b6de4f14261][Front matter]]):

#+begin_example
#+title:      My sample note file
#+date:       [2022-08-05 Fri 13:10]
#+filetags:   :testing:
#+identifier: 20220805T131044
#+end_example

Its file name reflects this information:

: 20220805T131044--my-sample-note-file__testing.org

You want to change its title and keywords manually, so you modify it thus:

#+begin_example
#+title:      My modified sample note file
#+date:       [2022-08-05 Fri 13:10]
#+filetags:   :testing:denote:emacs:
#+identifier: 20220805T131044
#+end_example

The file name still shows the old title and keywords.  So after saving
the buffer, you invoke ~denote-rename-file-using-front-matter~ and it
updates the file name to:

: 20220805T131044--my-modified-sample-note-file__testing_denote_emacs.org

The renaming is subject to a "yes or no" prompt that shows the old and
new names, just so the user is certain about the change.

If called interactively with a prefix argument =C-u= or from Lisp with
a non-nil =AUTO-CONFIRM= argument, this "yes or no" prompt is skipped.

The identifier of the file, if any, is never modified even if it is
edited in the front matter: Denote considers the file name to be the
source of truth in this case, to avoid potential breakage with typos and
the like.

** Rename multiple files based on their front matter
:PROPERTIES:
:CUSTOM_ID: h:ea5673cd-e6ca-4c42-a066-07dc6c9d57f8
:END:

#+findex: denote-dired-rename-marked-files-using-front-matter
As already noted, Denote can rename a file based on the data in its
front matter ([[#h:3ab08ff4-81fa-4d24-99cb-79f97c13a373][Rename a single file based on its front matter]]).  The
command ~denote-dired-rename-marked-files-using-front-matter~ extends
this principle to a batch operation which applies to all marked files in
Dired.

Marked files must count as notes for the purposes of Denote, which means
that they at least have an identifier in their file name and use a
supported file type, per ~denote-file-type~.  Files that do not meet
this criterion are ignored.

The operation does the following:

- the title in the front matter becomes the =TITLE= component of the
  file name ([[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file-naming scheme]]);

- the keywords in the front matter are used for the =KEYWORDS= component
  of the file name and are processed accordingly, if needed;

- the identifier remains unchanged in the file name even if it is
  modified in the front matter (this is done to avoid breakage caused by
  typos and the like).

NOTE that files must be saved, because Denote reads from the underlying
file, not a modified buffer (this is done to avoid potential mistakes).
The return value of a modified buffer is the one prior to the
modification, i.e. the one already written on disk.

This command is useful for synchronizing multiple file names with their
respective front matter.

* The file-naming scheme
:PROPERTIES:
:CUSTOM_ID: h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d
:END:

#+vindex: denote-directory
Notes are stored the ~denote-directory~.  The default path is
=~/Documents/notes=.  The ~denote-directory~ can be a flat listing,
meaning that it has no subdirectories, or it can be a directory tree.
Either way, Denote takes care to only consider "notes" as valid
candidates in the relevant operations and will omit other files or
directories.

Every note produced by Denote follows this pattern ([[#h:17896c8c-d97a-4faa-abf6-31df99746ca6][Points of entry]]):

: DATE--TITLE__KEYWORDS.EXTENSION

The =DATE= field represents the date in year-month-day format followed
by the capital letter =T= (for "time") and the current time in
hour-minute-second notation.  The presentation is compact:
=20220531T091625=.  The =DATE= serves as the unique identifier of each
note.

The =TITLE= field is the title of the note, as provided by the user.  It
automatically gets downcased and hyphenated.  An entry about "Economics
in the Euro Area" produces an =economics-in-the-euro-area= string for
the =TITLE= of the file name.

#+vindex: denote-allow-multi-word-keywords
The =KEYWORDS= field consists of one or more entries demarcated by an
underscore (the separator is inserted automatically).  Each keyword is a
string provided by the user at the relevant prompt which broadly
describes the contents of the entry.  Keywords that need to be more than
one-word-long must be written with hyphens: any other character, such as
spaces or the plus sign is automatically converted into a hyphen.  So
when =emacs_library= appears in a file name, it is interpreted as two
distinct keywords, whereas =emacs-library= is one keyword.  This is
reflected in how the keywords are recorded in the note ([[#h:13218826-56a5-482a-9b91-5b6de4f14261][Front matter]]).
While Denote supports multi-word keywords by default, the user option
~denote-allow-multi-word-keywords~ can be set to nil to forcibly join
all words into one, meaning that an input of =word1 word2= will be
written as =word1word2=.

#+vindex: denote-file-type
The =EXTENSION= is the file type.  By default, it is =.org= (~org-mode~)
though the user option ~denote-file-type~ provides support for Markdown
with YAML or TOML variants (=.md= which runs ~markdown-mode~) and plain
text (=.txt= via ~text-mode~).  Consult its doc string for the minutiae.
While files end in the =.org= extension by default, the Denote code base
does not actually depend on org.el and/or its accoutrements.

Examples:

: 20220610T043241--initial-thoughts-on-the-zettelkasten-method__notetaking.org
: 20220610T062201--define-custom-org-hyperlink-type__denote_emacs_package.md
: 20220610T162327--on-hierarchy-and-taxis__notetaking_philosophy.txt

The different field separators, namely =--= and =__= introduce an
efficient way to anchor searches (such as with Emacs commands like
~isearch~ or from the command-line with ~find~ and related).  A query
for =_word= always matches a keyword, while a regexp in the form of,
say, ="\\([0-9T]+?\\)--\\(.*?\\)_"= captures the date in group =\1= and
the title in =\2= (test any regular expression in the current buffer by
invoking =M-x re-builder=).

[[#h:1a953736-86c2-420b-b566-fb22c97df197][Features of the file-naming scheme for searching or filtering]].

While Denote is an Emacs package, notes should work long-term and not
depend on the functionality of a specific program.  The file-naming
scheme we apply guarantees that a listing is readable in a variety of
contexts.

** Sluggified title and keywords
:PROPERTIES:
:CUSTOM_ID: h:ae8b19a1-7f67-4258-96b3-370a72c43f4e
:END:

Denote has to be highly opinionated about which characters can be used
in file names and the file's front matter in order to enforce its
file-naming scheme.  The private variable ~denote--punctuation-regexp~
holds the relevant value.  In simple terms:

+ What we count as "illegal characters" are converted into hyphens.

+ Input for a file title is hyphenated and downcased.  The original
  value is preserved in the note's contents ([[#h:13218826-56a5-482a-9b91-5b6de4f14261][Front matter]]).

+ Keywords should not have spaces or other delimiters.  If they do, they
  are converted into hyphens.  Keywords are always downcased.

** Features of the file-naming scheme for searching or filtering
:PROPERTIES:
:CUSTOM_ID: h:1a953736-86c2-420b-b566-fb22c97df197
:END:

File names have three fields and two sets of field delimiters between
them:

: DATE--TITLE__KEYWORDS.EXTENSION

The first field delimiter is the double hyphen, while the second is the
double underscore.  These practically serve as anchors for easier
searching.  Consider this example:

: 20220621T062327--introduction-to-denote__denote_emacs.txt

You will notice that there are two matches for the word =denote=: one in
the title field and another in the keywords' field.  Because of the
distinct field delimiters, if we search for =-denote= we only match the
first instance while =_denote= targets the second one.  When sorting
through your notes, this kind of specificity is invaluable---and you get
it for free from the file names alone!

Users can get a lot of value out of this simple arrangement, even if
they have no knowledge of regular expressions.  One thing to consider,
for maximum effect, is to avoid using multi-word keywords as those get
hyphenated like the title and will thus interfere with the above: either
set the user option ~denote-allow-multi-word-keywords~ to nil or simply
insert single words at the relevant prompts.

* Front matter
:PROPERTIES:
:CUSTOM_ID: h:13218826-56a5-482a-9b91-5b6de4f14261
:END:

Notes have their own "front matter".  This is a block of data at the top
of the file, with no empty lines between the entries, which is
automatically generated at the creation of a new note.  The front matter
includes the title and keywords (aka "tags" or "filetags", depending on
the file type) which the user specified at the relevant prompt, as well
as the date and unique identifier, which are derived automatically.

This is how it looks for Org mode (when ~denote-file-type~ is nil or the
=org= symbol):

#+begin_example
#+title:      This is a sample note
#+date:       [2022-06-30 Thu 16:09]
#+filetags:   :denote:testing:
#+identifier: 20220630T160934
#+end_example

For Markdown with YAML (~denote-file-type~ has the =markdown-yaml=
value), the front matter looks like this:

#+begin_example
---
title:      "This is a sample note"
date:       2022-06-30T16:09:58+03:00
tags:       ["denote", "testing"]
identifier: "20220630T160958"
---
#+end_example

For Markdown with TOML (~denote-file-type~ has the =markdown-toml=
value), it is:

#+begin_example
+++
title      = "This is a sample note"
date       = 2022-06-30T16:10:13+03:00
tags       = ["denote", "testing"]
identifier = "20220630T161013"
+++
#+end_example

And for plain text (~denote-file-type~ has the =text= value), we have
the following:

#+begin_example
title:      This is a sample note
date:       2022-06-30
tags:       denote  testing
identifier: 20220630T161028
---------------------------
#+end_example

#+vindex: denote-date-format
The format of the date in the front matter is controlled by the user
option ~denote-date-format~.  When nil, Denote uses a file-type-specific
format:

- For Org, an inactive timestamp is used, such as
  =[2022-06-30 Wed 15:31]=.

- For Markdown, the RFC3339 standard is applied:
  =2022-06-30T15:48:00+03:00=.

- For plain text, the format is that of ISO 8601: =2022-06-30=.

If the value is a string, ignore the above and use it instead.  The
string must include format specifiers for the date.  These are described
in the doc string of ~format-time-string~..

** Change the front matter format
:PROPERTIES:
:CUSTOM_ID: h:7f918854-5ed4-4139-821f-8ee9ba06ad15
:END:

Per Denote's design principles, the code is hackable.  All front matter
is stored in variables that are intended for public use.  We do not
declare those as "user options" because (i) they expect the user to have
some degree of knowledge in Emacs Lisp and (ii) implement custom code.

[ NOTE for tinkerers: code intended for internal use includes double
  hyphens in its symbol.  "Internal use" means that it can be changed
  without warning and with no further reference in the change log.  Do
  not use any of it without understanding the consequences. ]

The variables which hold the front matter format are:

#+vindex: denote-org-front-matter
- ~denote-org-front-matter~

#+vindex: denote-text-front-matter
- ~denote-text-front-matter~

#+vindex: denote-toml-front-matter
- ~denote-toml-front-matter~

#+vindex: denote-yaml-front-matter
- ~denote-yaml-front-matter~

These variables have a string value with specifiers that are used by the
~format~ function.  The formatting operation passes four arguments which
include the values of the given entries.  If you are an advanced user
who wants to edit this variable to affect how front matter is produced,
consider using something like =%2$s= to control where the Nth argument
is placed.

When editing the value, make sure to:

1. Not use empty lines inside the front matter block.

2. Insert at least one empty line after the front matter block and do
   not use any empty line before it.

These help with consistency and might prove useful if we ever need to
operate on the front matter as a whole.

With those granted, below are some examples.  The approach is the same
for all variables.

#+begin_src emacs-lisp
;; Like the default, but upcase the entries
(setq denote-org-front-matter
  "#+TITLE:      %s
#+DATE:       %s
#+FILETAGS:   %s
#+IDENTIFIER: %s
\n")

;; Change the order (notice the %N$s notation)
(setq denote-org-front-matter
  "#+title:      %1$s
#+filetags:   %3$s
#+date:       %2$s
#+identifier: %4$s
\n")

;; Remove the date
(setq denote-org-front-matter
  "#+title:      %1$s
#+filetags:   %3$s
#+identifier: %4$s
\n")

;; Remove the date and the identifier
(setq denote-org-front-matter
  "#+title:      %1$s
#+filetags:   %3$s
\n")
#+end_src

Note that ~setq~ has a global effect: it affects the creation of all new
notes.  Depending on the workflow, it may be preferrable to have a
custom command which ~let~ binds the different format.  We shall not
provide examples at this point as this is a more advanced feature and we
are not yet sure what the user's needs are.  Please provide feedback and
we shall act accordingly.

** Regenerate front matter
:PROPERTIES:
:CUSTOM_ID: h:54b48277-e0e5-4188-ad54-ef3db3b7e772
:END:

#+findex: denote-add-front-matter
Sometimes the user needs to produce new front matter for an existing
note.  Perhaps because they accidentally deleted a line and could not
undo the operation.  The command ~denote-add-front-matter~ can be used
for this very purpose.

In interactive use, ~denote-add-front-matter~ must be invoked from a
buffer that visits a Denote note.  It prompts for a title and then for
keywords.  These are the standard prompts we already use for note
creation, so the keywords' prompt allows minibuffer completion and the
input of multiple entries, each separated by a comma ([[#h:17896c8c-d97a-4faa-abf6-31df99746ca6][Points of entry]]).

The newly created front matter is added to the top of the file.

This command does not rename the file (e.g. to update the keywords).  To
rename a file by reading its front matter as input, the user can rely on
~denote-rename-file-using-front-matter~ ([[#h:532e8e2a-9b7d-41c0-8f4b-3c5cbb7d4dca][Renaming files]]).

Note that ~denote-add-front-matter~ is useful only for existing Denote
notes.  If the user needs to convert a generic text file to a Denote
note, they can use one of the command which first rename the file to
make it comply with our file-naming scheme and then add the relevant
front matter.

* Linking notes
:PROPERTIES:
:CUSTOM_ID: h:fc913d54-26c8-4c41-be86-999839e8ad31
:END:

Denote offers several commands for linking between notes.

All links target files which are Denote notes.  This means that they
have our file-naming scheme, are writable/regular (not directory, named
pipe, etc.), and use the appropriate file type extension (per
~denote-file-type~).  Furthermore, the files need to be inside the
~denote-directory~ or one of its subdirectories.  No other file is
recognised.

The following sections delve into the details.

** Adding a single link
:PROPERTIES:
:CUSTOM_ID: h:5e5e3370-12ab-454f-ba09-88ff44214324
:END:

#+findex: denote-link
The ~denote-link~ command inserts a link at point to an entry specified
at the minibuffer prompt.  Links are formatted depending on the file
type of current note.  In Org and plain text buffers, links are
formatted thus: =[[denote:IDENTIFIER][TITLE]]=.  While in Markdown they
are expressed as =[TITLE](denote:IDENTIFIER)=.

When ~denote-link~ is called with a prefix argument (=C-u= by default),
it formats links like =[[denote:IDENTIFIER]]=.  The user might prefer
its simplicity.

The description of the link is taken from the target file's front
matter or, if that is not available, from the file name.  If the
region is active, its text is used as the link's description instead.
If the active region has no text, the inserted link used just the
identifier, as with the =C-u= prefix mentioned above.

Inserted links are automatically buttonized and remain active for as
long as the buffer is available.  In Org this is handled by the major
mode: the =denote:= hyperlink type works exactly like the standard
=file:=.  In Markdown and plain text, Denote performs the buttonization
of those links.  To buttonize links in existing files while visiting
them, the user must add this snippet to their setup (it already excludes
Org):

#+findex: denote-link-buttonize-buffer
#+begin_src emacs-lisp
(add-hook 'find-file-hook #'denote-link-buttonize-buffer)
#+end_src

The ~denote-link-buttonize-buffer~ is also an interactive function in
case the user needs it.

Links are created only for files which qualify as a "note" for our
purposes ([[#h:fc913d54-26c8-4c41-be86-999839e8ad31][Linking notes]]).

#+vindex: denote-faces-link
Links are styled with the ~denote-faces-link~ face, which looks exactly
like an ordinary link by default.  This is just a convenience for the
user/theme in case they want =denote:= links to remain distinct from
other links.

** Insert links matching a regexp
:PROPERTIES:
:CUSTOM_ID: h:9bec2c83-36ca-4951-aefc-7187c5463f90
:END:

#+findex: denote-link-add-links
The command ~denote-link-add-links~ adds links at point matching a
regular expression or plain string.  The links are inserted as a
typographic list, such as:

#+begin_example
- link1
- link2
- link3
#+end_example

Each link is formatted according to the file type of the current note,
as explained further above about the ~denote-link~ command.  The current
note is excluded from the matching entries (adding a link to itself is
pointless).

When called with a prefix argument (=C-u=) ~denote-link-add-links~ will
format all links as =[[denote:IDENTIFIER]]=, hence a typographic list:

#+begin_example
- [[denote:IDENTIFIER-1]]
- [[denote:IDENTIFIER-2]]
- [[denote:IDENTIFIER-3]]
#+end_example

Same examples of a regular expression that can be used with this
command:

- =journal= match all files which include =journal= anywhere in their
  name.

- =_journal= match all files which include =journal= as a keyword.

- =^2022.*_journal= match all file names starting with =2022= and
  including the keyword =journal=.

- =\.txt= match all files including =.txt=.  In practical terms, this
  only applies to the file extension, as Denote automatically removes
  dots (and other characters) from the base file name.

If files are created with ~denote-sort-keywords~ as non-nil (the
default), then it is easy to write a regexp that includes multiple
keywords in alphabetic order:

- =_denote.*_package= match all files that include both the =denote= and
  =package= keywords, in this order.

- =\(.*denote.*package.*\)\|\(.*package.*denote.*\)= is the same as
  above, but out-of-order.

Remember that regexp constructs only need to be escaped once (like =\|=)
when done interactively but twice when called from Lisp.  What we show
above is for interactive usage.

Links are created only for files which qualify as a "note" for our
purposes ([[#h:fc913d54-26c8-4c41-be86-999839e8ad31][Linking notes]]).

** Insert links, but only those missing from current buffer
:PROPERTIES:
:CUSTOM_ID: h:0c1fdaab-5a6b-4792-9694-fed53cd042e6
:END:

#+findex: denote-link-add-missing-links
As a variation on the ~denote-link-add-links~ command, one may wish to
only include 'missing links', i.e. links that are not yet present in
the current file.

This can be achieved with ~denote-link-add-missing-links~. The command
is similar to ~denote-link-add-links~, but will only include links to
notes that are not yet linked to ([[#h:9bec2c83-36ca-4951-aefc-7187c5463f90][Insert links matching a regexp]]).

** Insert links from marked files in Dired
:PROPERTIES:
:CUSTOM_ID: h:9cbb692e-5d8a-44a6-9193-899a07872a07
:END:

#+findex: denote-link-dired-marked-notes
The command ~denote-link-dired-marked-notes~ is similar to
~denote-link-add-links~ in that it inserts in the buffer a typographic
list of links to Denote notes ([[#h:9bec2c83-36ca-4951-aefc-7187c5463f90][Insert links matching a regexp]]).  Though
instead of reading a regular expression, it lets the user mark files in
Dired and link to them.  This should be easier for users of all skill
levels, instead of having to write a potentially complex regular
expression.

If there are multiple buffers that visit a Denote note, this command
will ask to select one among them, using minibuffer completion.  If
there is only one buffer, it will operate in it outright.  If there are
no buffers, it will produce an error.

With optional =ID-ONLY= as a prefix argument (=C-u= by default), the
command inserts links with just the identifier, which is the same
principle as with ~denote-link~ and others ([[#h:5e5e3370-12ab-454f-ba09-88ff44214324][Adding a single link]]).

The command ~denote-link-dired-marked-notes~ is meant to be used from a
Dired buffer.

As always, links are created only for files which qualify as a "note"
for our purposes ([[#h:fc913d54-26c8-4c41-be86-999839e8ad31][Linking notes]]).

** Link to an existing note or create a new one
:PROPERTIES:
:CUSTOM_ID: h:9e41e7df-2aac-4835-94c5-659b6111e6de
:END:

In one's note-taking workflow, there may come a point where they are
expounding on a certain topic but have an idea about another subject
they would like to link to ([[#h:fc913d54-26c8-4c41-be86-999839e8ad31][Linking notes]]).  The user can always rely on
the other linking facilities we have covered herein to target files that
already exist.  Though they may not know whether they already have notes
covering the subject or whether they would need to write new ones.  To
this end, Denote provides two convenience commands:

#+findex: denote-link-after-creating
+ ~denote-link-after-creating~ :: Create new note in the background and
  link to it directly.

  Use ~denote~ interactively to produce the new note.  Its doc string or
  this manual explains which prompts will be used and under what
  conditions ([[#h:6a92a8b5-d766-42cc-8e5b-8dc255466a23][Standard note creation]]).

  With optional =ID-ONLY= as a prefix argument (this is the =C-u= key,
  by default) create a link that consists of just the identifier.  Else
  try to also include the file's title.  This has the same meaning as in
  ~denote-link~ ([[#h:5e5e3370-12ab-454f-ba09-88ff44214324][Adding a single link]]).

  IMPORTANT NOTE: Normally, ~denote~ does not save the buffer it
  produces for the new note.  This is a safety precaution to not write
  to disk unless the user wants it (e.g. the user may choose to kill the
  buffer, thus cancelling the creation of the note).  However, for this
  command the creation of the note happens in the background and the
  user may miss the step of saving their buffer.  We thus have to save
  the buffer in order to (i) establish valid links, and (ii) retrieve
  whatever front matter from the target file.

#+findex: denote-link-or-create
+ ~denote-link-or-create~ :: Use ~denote-link~ on =TARGET= file,
  creating it if necessary.

  If =TARGET= file does not exist, call ~denote-link-after-creating~
  which runs the ~denote~ command interactively to create the file.  The
  established link will then be targeting that new file.

  If =TARGET= file does not exist, add the user input that was used to
  search for it to the history of the ~denote-title-prompt~.  The user
  can then retrieve and possibly further edit their last input, using
  it as the newly created note's actual title.  At the ~denote-title-prompt~
  type =M-p= with the default key bindings, which calls ~previous-history-element~.

  With optional =ID-ONLY= as a prefix argument create a link with just
  the file's identifier.  This has the same meaning as in ~denote-link~.

  This command has the alias ~denote-link-to-existing-or-new-note~,
  which helps with discoverability.

** The backlinks' buffer
:PROPERTIES:
:CUSTOM_ID: h:c73f1f68-e214-49d5-b369-e694f6a5d708
:END:

#+findex: denote-link-backlinks
The command ~denote-link-backlinks~ produces a bespoke buffer which
displays backlinks to the current note.  A "backlink" is a link back
to the present entry.

By default, the backlinks' buffer is desinged to display the file name
of the note linking to the current entry.  Each file name is presented
on its own line, like this:

#+begin_example
Backlinks to "On being honest" (20220614T130812)
------------------------------------------------

20220614T145606--let-this-glance-become-a-stare__journal.txt
20220616T182958--feeling-butterflies-in-your-stomach__journal.txt
#+end_example

#+vindex: denote-backlinks-show-context
When the user option ~denote-backlinks-show-context~ is non-nil, the
backlinks' buffer displays the line on which a link to the current
note occurs.  It also shows multiple occurances, if present.  It looks
like this (and has the appropriate fontification):

#+begin_example
Backlinks to "On being honest" (20220614T130812)
------------------------------------------------

20220614T145606--let-this-glance-become-a-stare__journal.txt
37: growing into it: [[denote:20220614T130812][On being honest]].
64: As I said in [[denote:20220614T130812][On being honest]] I have never
20220616T182958--feeling-butterflies-in-your-stomach__journal.txt
62: indifference.  In [[denote:20220614T130812][On being honest]] I alluded
#+end_example

Note that the width of the lines in the context depends on the
underlying file.  In the above example, the lines are split at the
~fill-column~.  Long lines will show up just fine.  Also note that the
built-in user option ~xref-truncation-width~ can truncate long lines
to a given maximum number of characters.

[[#h:893eec49-d7be-4603-bcff-fcc247244011][Speed up backlinks' buffer creation?]]

#+findex: denote-backlinks-mode
#+vindex: denote-backlinks-mode-map
The backlinks' buffer runs the major-mode ~denote-backlinks-mode~.  It
binds keys to move between links with =n= (next) and =p= (previous).
These are stored in the ~denote-backlinks-mode-map~ (use =M-x
describe-mode= (=C-h m=) in an unfamiliar buffer to learn more about
it).  When the user option ~denote-backlinks-show-context~ is non-nil,
all relevant Xref key bindings are fully functional: again, check
~describe-mode~.

The backlinking facility uses Emacs' built-in Xref infrastructure.  On
some operating systems, the user may need to add certain executables
to the relevant environment variable.

[[#h:42f6b07e-5956-469a-8294-17f9cf62eb2b][Why do I get "Search failed with status 1" when I search for backlinks?]]

Backlinks to the current file can also be visited by using the
minibuffer completion interface with the ~denote-link-find-backlink~
command ([[#h:1bc2adad-dca3-4878-b9f0-b105d5dec6f4][Visiting linked files via the minibuffer]]).

#+vindex: denote-link-backlinks-display-buffer-action
The placement of the backlinks' buffer is subject to the user option
~denote-link-backlinks-display-buffer-action~.  Due to the nature of the
underlying ~display-buffer~ mechanism, this inevitably is a relatively
advanced feature.  By default, the backlinks' buffer is displayed below
the current window.  The doc string of our user option includes a sample
configuration that places the buffer in a left side window instead.
Reproducing it here for the sake of convenience:

#+begin_src emacs-lisp
(setq denote-link-backlinks-display-buffer-action
      '((display-buffer-reuse-window
         display-buffer-in-side-window)
        (side . left)
        (slot . 99)
        (window-width . 0.3)))
#+end_src

** Writing metanotes
:PROPERTIES:
:CUSTOM_ID: h:6060a7e6-f179-4d42-a9de-a9968aaebecc
:END:

A "metanote" is an entry that describes other entries who have something
in common.  Writing metanotes can be part of a workflow where the user
periodically reviews their work in search of patterns and deeper
insights.  For example, you might want to read your journal entries from
the past year to reflect on your experiences, evolution as a person, and
the like.

The commands ~denote-link-add-links~, ~denote-link-dired-marked-notes~
are suited for this task.

[[#h:9bec2c83-36ca-4951-aefc-7187c5463f90][Insert links matching a regexp]].

[[#h:9cbb692e-5d8a-44a6-9193-899a07872a07][Insert links from marked files in Dired]].

You will create your metanote the way you use Denote ordinarily
(metanotes may have the =metanote= keyword, among others), write an
introduction or however you want to go about it, invoke the command
which inserts multiple links at once (see the above-cited nodes), and
continue writing.

Metanotes can serve as entry points to groupings of individual notes.
They are not the same as a filtered list of files, i.e. what you would
do in Dired or the minibuffer where you narrow the list of notes to a
given query.  Metanotes contain the filtered list plus your thoughts
about it.  The act of purposefully grouping notes together and
contemplating on their shared patterns is what adds value.

Your future self will appreciate metanotes for the function they serve
in encapsulating knowledge, while current you will be equipped with the
knowledge derived from the deliberate self-reflection.

** Visiting linked files via the minibuffer
:PROPERTIES:
:CUSTOM_ID: h:1bc2adad-dca3-4878-b9f0-b105d5dec6f4
:END:

#+findex: denote-link-find-file
Denote has a major-mode-agnostic mechanism to collect all linked file
references in the current buffer and return them as an appropriately
formatted list.  This list can then be used in interactive commands.
The ~denote-link-find-file~ is such a command.  It uses minibuffer
completion to visit a file that is linked to from the current note.  The
candidates have the correct metadata, which is ideal for integration
with other standards-compliant tools ([[#h:8ed2bb6f-b5be-4711-82e9-8bee5bb06ece][Extending Denote]]).  For instance,
a package such as =marginalia= will display accurate annotations, while
the =embark= package will be able to work its magic such as in exporting
the list into a filtered Dired buffer (i.e. a familiar Dired listing
with only the files of the current minibuffer session).

#+findex: denote-link-find-backlink
To visit backlinks to the current note via the minibuffer, use
~denote-link-find-backlink~.  This is an alternative to placing
backlinks in a dedicated buffer ([[#h:c73f1f68-e214-49d5-b369-e694f6a5d708][The backlinks' buffer]]).

** Miscellaneous information about links
:PROPERTIES:
:CUSTOM_ID: h:dd8f2231-8d77-49b9-acc4-af525c68b271
:END:

#+findex: denote-link-insert-link
#+findex: denote-link-show-backlinks-buffer
#+findex: denote-link-insert-links-matching-regexp
For convenience, the ~denote-link~ command has an alias called
~denote-link-insert-link~.  The ~denote-link-backlinks~ can also be used
as ~denote-link-show-backlinks-buffer~.  While ~denote-link-add-links~
is aliased ~denote-link-insert-links-matching-regexp~.  The purpose of
these aliases is to offer alternative, more descriptive names of select
commands.

* Fontification in Dired
:PROPERTIES:
:CUSTOM_ID: h:337f9cf0-9f66-45af-b73f-f6370472fb51
:END:

#+findex: denote-dired-mode
One of the upsides of Denote's file-naming scheme is the predictable
pattern it establishes, which appears as a near-tabular presentation in
a listing of notes (i.e. in Dired).  The ~denote-dired-mode~ can help
enhance this impression, by fontifying the components of the file name
to make the date (identifier) and keywords stand out.

There are two ways to set the mode.  Either use it for all directories,
which probably is not needed:

#+begin_src emacs-lisp
(add-hook 'dired-mode-hook #'denote-dired-mode)
#+end_src

#+vindex: denote-dired-directories
#+findex: denote-dired-mode-in-directories
Or configure the user option ~denote-dired-directories~ and then set up
the function ~denote-dired-mode-in-directories~:

#+begin_src emacs-lisp
;; We use different ways to specify a path for demo purposes.
(setq denote-dired-directories
      (list denote-directory
            (thread-last denote-directory (expand-file-name "attachments"))
            (expand-file-name "~/Documents/vlog")))

(add-hook 'dired-mode-hook #'denote-dired-mode-in-directories)
#+end_src

The faces we define for this purpose are:

#+vindex: denote-faces-date
#+vindex: denote-faces-delimiter
#+vindex: denote-faces-extension
#+vindex: denote-faces-keywords
#+vindex: denote-faces-subdirectory
#+vindex: denote-faces-time
#+vindex: denote-faces-title
+ ~denote-faces-date~
+ ~denote-faces-delimiter~
+ ~denote-faces-extension~
+ ~denote-faces-keywords~
+ ~denote-faces-subdirectory~
+ ~denote-faces-time~
+ ~denote-faces-title~

For the time being, the =diredfl= package is not compatible with this
facility.

The ~denote-dired-mode~ does not only fontify note files that were
created by Denote: it covers every file name that follows our naming
conventions ([[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file-naming scheme]]).  This is particularly useful for
scenaria where, say, one wants to organise their collection of PDFs and
multimedia in a systematic way (and, perhaps, use them as attachments
for the notes Denote produces if you are writing Org notes and are using
its standand attachments' facility).

* Use Org dynamic blocks
:PROPERTIES:
:CUSTOM_ID: h:8b542c50-dcc9-4bca-8037-a36599b22779
:END:

Denote can optionally integrate with Org mode's "dynamic blocks"
facility.  Start by loading the relevant library:

#+begin_src emacs-lisp
;; Register Denote's Org dynamic blocks
(require 'denote-org-dblock)
#+end_src

A dynamic block gets its contents by evaluating a given function,
depending on the type of block.  The type of block and its parameters
are stated in the opening =#+BEGIN= line of the block.  Typing =C-c C-c=
with point on that line runs the function, with the given arguments,
and populates the block's contents accordingly.

Denote leverages Org dynamic blocks to streamline the inclusion of (i)
links to notes whose name matches a given search query (like
~denote-link-add-links~) and (ii) backlinks to the current note (similar to
~denote-link-find-backlink~).

These two types of blocks are named =denote-links= and =denote-backlinks=
respectively.  The latter does not accept any parameters, while the
former does, which we explain below by also demonstrating how dynamic
blocks are written.

A dynamic block looks like this:

: #+BEGIN: denote-links :regexp "_journal"
:
: #+END:

Here we have the =denote-links= type, with the =:regexp= parameter.
The value of the =:regexp= parameter is the same as that of the
command ~denote-link-add-links~ ([[#h:9bec2c83-36ca-4951-aefc-7187c5463f90][Insert links matching a regexp]]).  The
linked entry provides practical examples of patterns that make good
use of Denote's file-naming scheme ([[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file-naming scheme]]).

In this example, we instruct Org to produce a list of all notes that
include the =journal= keyword in their file name (keywords in file
names are prefixed with the underscore).  So the following:

: #+BEGIN: denote-links :regexp "_journal"
:
: #+END:

Becomes something like this once we type =C-c C-c= with point on the
=#+BEGIN= line (Org makes the links look prettier by default):

: #+BEGIN: denote-links :regexp "_journal"
: - [[denote:20220616T182958][Feeling butterflies in your stomach]]
: - [[denote:20220818T221036][Between friend and stranger]]
: #+END:

The dynamic block takes care to keep the list in order and to add any
missing links when the block is evaluated anew.

Depending on one's workflow, the dynamic block can be instructed to
list only those links which are missing from the current buffer
(similar to ~denote-link-add-missing-links~).  Adding the =:missing-only=
parameter with a non-~nil~ value achieves this effect. The =#+BEGIN= line
looks like this:

: #+BEGIN: denote-links :regexp "_journal" :missing-only t

To reverse the order links appear in, add =:reverse t= to the
=#+BEGIN= line.

The =denote-links= block can also accept a =:block-name= parameter
with a string value that names the block.  Once the dynamic block is
evaluated, a =#+NAME= is prepended to the block's contents.  This can
be referenced in other source blocks to parse the named block's
contents as input of another process.  The details are beyond the
scope of Denote.

As for the =denote-backlinks= dynamic block type, it simply produces a
list of notes that link to the current file.  It accepts no parameters
and looks like this:

: #+BEGIN: denote-backlinks
:
: #+END:

The Org manual describes the technicalities of Dynamic Blocks.
Evaluate:

#+begin_src emacs-lisp
(info "(org) Dynamic Blocks")
#+end_src

Dynamic blocks are particularly useful for metanote entries that
reflect on the status of earlier notes ([[#h:6060a7e6-f179-4d42-a9de-a9968aaebecc][Writing metanotes]]).

* Minibuffer histories
:PROPERTIES:
:CUSTOM_ID: h:82dc1203-d689-44b2-9a6c-b37776209651
:END:

Denote has a dedicated minibuffer history for each one of its prompts.
This practically means that using =M-p= (~previous-history-element~) and
=M-n= (~next-history-element~) will only cycle through the relevant
record of inputs, such as your latest titles in the =TITLE= prompt, and
keywords in the =KEYWORDS= prompt.

The built-in =savehist= library saves minibuffer histories.  Sample
configuration:

#+begin_src emacs-lisp
(require 'savehist)
(setq savehist-file (locate-user-emacs-file "savehist"))
(setq history-length 500)
(setq history-delete-duplicates t)
(setq savehist-save-minibuffer-history t)
(add-hook 'after-init-hook #'savehist-mode)
#+end_src

* Extending Denote
:PROPERTIES:
:CUSTOM_ID: h:8ed2bb6f-b5be-4711-82e9-8bee5bb06ece
:END:

Denote is a tool with a narrow scope: create notes and link between
them, based on the aforementioned file-naming scheme.  For other common
operations the user is advised to rely on standard Emacs facilities or
specialised third-party packages.  This section covers the details.

** Keep a journal or diary
:PROPERTIES:
:CUSTOM_ID: h:4a6d92dd-19eb-4fcc-a7b5-05ce04da3a92
:END:

While there are subtle technical differences between a journal and a
diary, we will consider those equivalent in the interest of brevity:
they both describe a personal space that holds a record of your thoughts
about your experiences and/or view of events in the world.

Suppose you are committed to writing an entry every day.  Unlike what we
demonstrated before, your writing will follow a regular naming pattern.
You know that the title of the new note must always look like =Tuesday
14 June 2022= and the keyword has to be =journal= or =diary=.  As such,
you want to automate the task instead of being prompted each time, as is
the norm with ~denote~ and the relevant commands ([[#h:17896c8c-d97a-4faa-abf6-31df99746ca6][Points of entry]]).
This is easy to accomplish because ~denote~ can be called from Lisp and
given the required arguments of =TITLE= and =KEYWORDS= directly.  All
you need is a simple wrapper function:

#+begin_src emacs-lisp
(defun my-denote-journal ()
  "Create an entry tagged 'journal' with the date as its title."
  (interactive)
  (denote
   (format-time-string "%A %e %B %Y") ; format like Tuesday 14 June 2022
   '("journal"))) ; multiple keywords are a list of strings: '("one" "two")
#+end_src

By invoking ~my-denote-journal~ you will go straight into the newly
created note and commit to your writing outright.

Of course, you can always set up the function so that it asks for a
=TITLE= but still automatically applies the =journal= tag:

#+begin_src emacs-lisp
(defun denote-journal-with-title ()
  "Create an entry tagged 'journal', while prompting for a title."
  (interactive)
  (denote
   (denote--title-prompt) ; ask for title, instead of using human-readable date
   '("journal")))
#+end_src

Sometimes journaling is done with the intent to hone one's writing
skills.  Perhaps you are learning a new language or wish to communicate
your ideas with greater clarity and precision.  As with everything that
requires a degree of sophistication, you have to work for it---write,
write, write!

One way to test your progress is to set a timer.  It helps you gauge
your output and its quality.  To use a timer with Emacs, consider the
=tmr= package:

#+begin_src emacs-lisp
(defun my-denote-journal-with-tmr ()
  "Like `my-denote-journal', but also set a 10-minute timer.
The `tmr' command is part of the `tmr' package."
  (interactive)
  (denote
   (format-time-string "%A %e %B %Y")
   '("journal"))
  (tmr "10" "Practice writing in my journal")) ; set 10 minute timer with a description
#+end_src

Once the timer elapses, stop writing and review your performance.
Practice makes perfect!

[ As Denote matures, we may add hooks to control what happens before or
  after the creation of a new note.  We shall also document more
  examples of tasks that can be accomplished with this package. ]

Sources for =tmr=:

+ Package name (GNU ELPA): =tmr=
+ Official manual: <https://protesilaos.com/emacs/tmr>
+ Change log: <https://protesilaos.com/emacs/denote-changelog>
+ Git repo on SourceHut: <https://git.sr.ht/~protesilaos/tmr>
  - Mirrors:
    + GitHub: <https://github.com/protesilaos/tmr>
    + GitLab: <https://gitlab.com/protesilaos/tmr>
+ Mailing list: <https://lists.sr.ht/~protesilaos/tmr>

** Create a note with the region's contents
:PROPERTIES:
:CUSTOM_ID: h:2f8090f1-50af-4965-9771-d5a91a0a87bd
:END:

Sometimes it makes sense to gather notes in a single file and later
review it to make multiple notes out of it.  With the following code,
the user marks a region and then invokes the command
~my-denote-create-new-note-from-region~: it prompts for a title and
keywords and then uses the region's contents to fill in the newly
created note.

#+begin_src emacs-lisp
(defun my-denote-create-new-note-from-region (beg end)
  "Create note whose contents include the text between BEG and END.
Prompt for title and keywords of the new note."
  (interactive "r")
  (if-let (((region-active-p))
           (text (buffer-substring-no-properties beg end)))
      (progn
        (denote (denote--title-prompt) (denote--keywords-prompt))
        (insert text))
    (user-error "No region is available")))
#+end_src

Have a different workflow?  Feel welcome to discuss it in any of our
official channels ([[#h:1ebe4865-c001-4747-a6f2-0fe45aad71cd][Contributing]]).

** Split an Org subtree into its own note
:PROPERTIES:
:CUSTOM_ID: h:d0c7cb79-21e5-4176-a6af-f4f68578c8dd
:END:

With Org files in particular, it is common to have nested headings
which could be split off into their own standalone notes.  In Org
parlance, an entry with all its subheadings is a "subtree".  With the
following code, the user places the point inside the heading they want
to split off and invokes the command ~my-denote-org-extract-subtree~.
It will create a note using the heading's text and tags for the new
file.  The contents of the subtree become the contents of the new note
and are removed from the old one.

#+begin_src emacs-lisp
(defun my-denote-org-extract-subtree ()
  "Create new Denote note using current Org subtree.
Make the new note use the Org file type, regardless of the value
of `denote-file-type'.

Use the subtree title as the note's title.  If available, use the
tags of the heading are used as note keywords.

Delete the original subtree."
  (interactive)
  (if-let ((text (org-get-entry))
           (heading (org-get-heading :no-tags :no-todo :no-priority :no-comment)))
      (progn
        (delete-region (org-entry-beginning-position) (org-entry-end-position))
        (denote heading (org-get-tags) 'org)
        (insert text))
    (user-error "No subtree to extract; aborting")))
#+end_src

Have a different workflow?  Feel welcome to discuss it in any of our
official channels ([[#h:1ebe4865-c001-4747-a6f2-0fe45aad71cd][Contributing]]).

** Narrow the list of files in Dired
:PROPERTIES:
:CUSTOM_ID: h:ea173a01-69ef-4574-89a7-6e60ede02f13
:END:

Emacs' standard file manager (or directory editor) can read a regular
expression to mark the matching files.  This is the command
~dired-mark-files-regexp~, which is bound to =% m= by default.  For
example, =% m _denote= will match all files that have the =denote=
keyword ([[#h:1a953736-86c2-420b-b566-fb22c97df197][Features of the file-naming scheme for searching or filtering]]).

Once the files are matched, the user has to options: (i) narrow the list
to the matching items or (ii) exclude the matching items from the list.

For the former, we want to toggle the marks by typing =t= (calls the
command ~dired-toggle-marks~ by default) and then hit the letter =k=
(for ~dired-do-kill-lines~).  The remaining files are those that match
the regexp that was provided earlier.

For the latter approach of filtering out the matching items, simply
involves the use of the =k= command (~dired-do-kill-lines~) to omit the
marked files from the list.

These sequences can be combined to incrementally narrow the list.  Note
that ~dired-do-kill-lines~ does not delete files: it simply hides them
from the current view.

Revert to the original listing with =g= (~revert-buffer~).

For a convenient wrapper, consider this example:

#+begin_src emacs-lisp
(defvar prot-dired--limit-hist '()
  "Minibuffer history for `prot-dired-limit-regexp'.")

;;;###autoload
(defun prot-dired-limit-regexp (regexp omit)
  "Limit Dired to keep files matching REGEXP.

With optional OMIT argument as a prefix (\\[universal-argument]),
exclude files matching REGEXP.

Restore the buffer with \\<dired-mode-map>`\\[revert-buffer]'."
  (interactive
   (list
    (read-regexp
     (concat "Files "
             (when current-prefix-arg
               (propertize "NOT " 'face 'warning))
             "matching PATTERN: ")
     nil 'prot-dired--limit-hist)
    current-prefix-arg))
  (dired-mark-files-regexp regexp)
  (unless omit (dired-toggle-marks))
  (dired-do-kill-lines))
#+end_src

** Use ~dired-virtual-mode~ for arbitrary file listings
:PROPERTIES:
:CUSTOM_ID: h:d35d8d41-f51b-4139-af8f-9c8cc508e35b
:END:

Emacs' Dired is a powerful file manager that builds its functionality
on top of the Unix =ls= command.  As noted elsewhere in this manual,
the user can update the =ls= flags that Dired uses to display its
contents ([[#h:a7fd5e0a-78f7-434e-aa2e-e150479c16e2][I want to sort by last modified, why won't Denote let me?]]).

What Dired cannot do is parse the output of a result that is produced
by piped commands, such as =ls -l | sort -t _ -k2=.  This specific
example targets the second underscore-separated field of the file
name, per our conventions ([[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file-naming scheme]]).  Conceretely, it
matches the "alpha" as the sorting key in something like this:

#+begin_src emacs-lisp
20220929T200432--testing-file-one__alpha.txt
#+end_src

Consider then, how Dired will sort those files by their identifier:

#+begin_src emacs-lisp
20220929T200432--testing-file-one__alpha.txt
20220929T200532--testing-file-two__beta.txt
20220929T200632--testing-file-three__alpha.txt
20220929T200732--testing-file-four__beta.txt
#+end_src

Whereas on the command line, we can get the following:

#+begin_example
$ ls | sort -t _ -k 2
20220929T200432--testing-file-one__alpha.txt
20220929T200632--testing-file-three__alpha.txt
20220929T200532--testing-file-two__beta.txt
20220929T200732--testing-file-four__beta.txt
#+end_example

This is where ~dired-virtual-mode~ shows its utility.  If we tweak our
command-line invocation to include =ls -l=, this mode can behave like
Dired on the listed files.  (We omit the output of the =-l= flag from
this tutorial, as it is too verbose.)

What we now need is to capture the output of =ls -l | sort -t _ -k 2=
in an Emacs buffer and then enable ~dired-virtual-mode~.  To do that,
we can rely on either =M-x shell= or =M-x eshell= and then manually
copy the relevant contents.

For the user's convenience, I share what I have for Eshell to quickly
capture the last command's output in a dedicated buffer:

#+begin_src emacs-lisp
(defcustom prot-eshell-output-buffer "*Exported Eshell output*"
  "Name of buffer with the last output of Eshell command.
Used by `prot-eshell-export'."
  :type 'string
  :group 'prot-eshell)

(defcustom prot-eshell-output-delimiter "* * *"
  "Delimiter for successive `prot-eshell-export' outputs.
This is formatted internally to have newline characters before
and after it."
  :type 'string
  :group 'prot-eshell)

(defun prot-eshell--command-prompt-output ()
  "Capture last command prompt and its output."
  (let ((beg (save-excursion
               (goto-char (eshell-beginning-of-input))
               (goto-char (point-at-bol)))))
    (when (derived-mode-p 'eshell-mode)
      (buffer-substring-no-properties beg (eshell-end-of-output)))))

;;;###autoload
(defun prot-eshell-export ()
  "Produce a buffer with output of the last Eshell command.
If `prot-eshell-output-buffer' does not exist, create it.  Else
append to it, while separating multiple outputs with
`prot-eshell-output-delimiter'."
  (interactive)
  (let ((eshell-output (prot-eshell--command-prompt-output)))
    (with-current-buffer (get-buffer-create prot-eshell-output-buffer)
      (let ((inhibit-read-only t))
        (goto-char (point-max))
        (unless (eq (point-min) (point-max))
          (insert (format "\n%s\n\n" prot-eshell-output-delimiter)))
        (goto-char (point-at-bol))
        (insert eshell-output)
        (switch-to-buffer-other-window (current-buffer))))))
#+end_src

Bind ~prot-eshell-export~ to a key in the ~eshell-mode-map~ and give
it a try (I use =C-c C-e=).  In the produced buffer, activate the
~dired-virtual-mode~.

** Use Embark to collect minibuffer candidates
:PROPERTIES:
:CUSTOM_ID: h:edf9b651-86eb-4d5f-bade-3c9e270082f0
:END:

=embark= is a remarkable package that lets you perform relevant,
context-dependent actions using a prefix key (simplifying in the
interest of brevity).

For our purposes, Embark can be used to produce a Dired listing directly
from the minibuffer.  Suppose the current note has links to three other
notes.  You might use the ~denote-link-find-file~ command to pick one
via the minibuffer.  But why not turn those three links into their own
Dired listing?  While in the minibuffer, invoke ~embark-act~ which you
may have already bound to =C-.= and then follow it up with =E= (for the
~embark-export~ command).

This pattern can be repeated with any list of candidates, meaning that
you can narrow the list by providing some input before eventually
exporting the results with Embark.

Overall, this is very powerful and you might prefer it over doing the
same thing directly in Dired, since you also benefit from all the power
of the minibuffer ([[#h:ea173a01-69ef-4574-89a7-6e60ede02f13][Narrow the list of files in Dired]]).

** Search file contents
:PROPERTIES:
:CUSTOM_ID: h:76198fab-d6d2-4c67-9ccb-7a08cc883952
:END:

Emacs provides built-in commands which are wrappers of standard Unix
tools: =M-x grep= lets the user input the flags of a ~grep~ call and
pass a regular expression to the =-e= flag.

The author of Denote uses this thin wrapper instead:

#+begin_src emacs-lisp
(defvar prot-search--grep-hist '()
  "Input history of grep searches.")

;;;###autoload
(defun prot-search-grep (regexp &optional recursive)
  "Run grep for REGEXP.

Search in the current directory using `lgrep'.  With optional
prefix argument (\\[universal-argument]) for RECURSIVE, run a
search starting from the current directory with `rgrep'."
  (interactive
   (list
    (read-from-minibuffer (concat (if current-prefix-arg
                                      (propertize "Recursive" 'face 'warning)
                                    "Local")
                                  " grep for PATTERN: ")
                          nil nil nil 'prot-search--grep-hist)
    current-prefix-arg))
  (unless grep-command
    (grep-compute-defaults))
  (if recursive
      (rgrep regexp "*" default-directory)
    (lgrep regexp "*" default-directory)))
#+end_src

Rather than maintain custom code, consider using the excellent =consult=
package: it provides commands such as ~consult-grep~ and ~consult-find~
which provide live results and are generally easier to use than the
built-in commands.

** Bookmark the directory with the notes
:PROPERTIES:
:CUSTOM_ID: h:1bba4c1e-6812-4749-948f-57df4fd49b36
:END:

Part of the reason Denote does not reinvent existing functionality is to
encourage you to learn more about Emacs.  You do not need a bespoke
"jump to my notes" directory because such commands do not scale well.
Will you have a "jump to my downloads" then another for multimedia and
so on?  No.

Emacs has a built-in framework for recording persistent markers to
locations.  Visit the ~denote-directory~ (or any dir/file for that
matter) and invoke the ~bookmark-set~ command (bound to =C-x r m= by
default).  It lets you create a bookmark.

The list of bookmarks can be reviewed with the ~bookmark-bmenu-list~
command (bound to =C-x r l= by default).  A minibuffer interface is
available with ~bookmark-jump~ (=C-x r b=).

If you use the =consult= package, its default ~consult-buffer~ command
has the means to group together buffers, recent files, and bookmarks.
Each of those types can be narrowed to with a prefix key.  The package
=consult-dir= is an extension to =consult= which provides useful extras
for working with directories, including bookmarks.

** Use the ~citar-denote~ package for bibliography notes
:PROPERTIES:
:CUSTOM_ID: h:226d66e4-b7de-4617-87e2-a7f2d6f007dd
:END:

Peter Prevos has produced the ~citar-denote~ package which makes it
possible to write notes on BibTeX entries with the help of the ~citar~
package.  These notes have the citation's unique key associated with
them in the file's front matter.  They also get a configurable keyword
in their file name, making it easy to find them in Dired and/or
retrieve them with the various Denote methods.

With ~citar-denote~, the user leverages standard minibuffer completion
mechanisms (e.g. with the help of the ~vertico~ and ~embark~ packages)
to manage bibliographic notes and access those notes with ease.  The
package's documentation covers the details: <https://github.com/pprevos/citar-denote/>.

** Use the ~consult-notes~ package
:PROPERTIES:
:CUSTOM_ID: h:8907f4bc-992a-45bc-a60e-267ed1ce9c2d
:END:

If you are already using ~consult~ (which is a brilliant package), you
will probably like its ~consult-notes~ extension.  It uses the familiar
mechanisms of Consult to filter searches via a prefix key.  For example:

#+begin_src emacs-lisp
(setq consult-notes-sources
      `(("Notes"  ?n ,denote-directory)
        ("Books"  ?b "~/Documents/books")))
#+end_src

With the above, =M-x consult-notes= will list the files in those two
directories.  If you type =n= and space, it narrows the list to just the
notes, while =b= does the same for books.

To search all your notes with grep (or ripgrep if installed -- see
~consult-notes-use-rg~ variable) use the command
~consult-notes-search-in-all-notes~. This will employ grep/ripgrep for
searching terms in all the directories set in ~consult-notes-sources~.

Note that ~consult-notes~ is in its early stages of development.
Expect improvements in the near future (written on 2022-06-22 16:48
+0300).

** Treat your notes as a project
:PROPERTIES:
:CUSTOM_ID: h:fad3eb08-ddc7-43e4-ba28-210d89668037
:END:

Emacs has a built-in library for treating a directory tree as a
"project".  This means that the contents of this tree are seen as part
of the same set, so commands like ~project-switch-to-buffer~ (=C-x p b=
by default) will only consider buffers in the current project
(e.g. three notes that are currently being visited).

Normally, a "project" is a directory tree whose root is under version
control.  For our purposes, all you need is to navigate to the
~denote-directory~ (for the shell or via Dired) and use the command-line
to run this (requires the =git= executable):

: git init

From Dired, you can type =M-!= which invokes ~dired-smart-shell-command~
and then run the git call there.

The project can then be registered by invoking any project-related
command inside of it, such as ~project-find-file~ (=C-x p f=).

It is a good idea to keep your notes under version control, as that
gives you a history of changes for each file.  We shall not delve into
the technicalities here, though suffice to note that Emacs' built-in
version control framework or the exceptionally well-crafted =magit=
package will get the job done (VC can work with other backends besides
Git).

** Variants of ~denote-open-or-create~
:PROPERTIES:
:CUSTOM_ID: h:ad91ca39-cf10-4e16-b224-fdf78f093883
:END:

#+findex: denote-open-or-create
The command ~denote-open-or-create~ prompts to visit a file in the
~denote-directory~.  If the user input does not have any matches,
~denote-open-or-create~ will call the ~denote~ command interactively.
It will then use whatever prompts ~denote~ normally has, per the user
option ~denote-prompts~ ([[#h:6a92a8b5-d766-42cc-8e5b-8dc255466a23][Standard note creation]]).

To speed up the process or to maintain variants that suit one's
workflow, we provide these ready-to-use commands that one can add to
their Emacs init file.  They can be assigned to key bindings or be used
via =M-x= after they have been evaluated.

#+begin_src emacs-lisp
;;;###autoload
(defun denote-open-or-create-with-date ()
  "Invoke `denote-open-or-create' but also prompt for date.

The date can be in YEAR-MONTH-DAY notation like 2022-06-30 or
that plus the time: 2022-06-16 14:30.  When the user option
`denote-date-prompt-use-org-read-date' is non-nil, the date
prompt uses the more powerful Org+calendar system.

This is the equivalent to calling `denote-open-or-create' when
`denote-prompts' is set to \\='(date title keywords)."
  (declare (interactive-only t))
  (interactive)
  (let ((denote-prompts '(date title keywords)))
    (call-interactively #'denote-open-or-create)))

;;;###autoload
(defun denote-open-or-create-with-type ()
  "Invoke `denote-open-or-create' but also prompt for file type.
This is the equivalent to calling `denote-open-or-create' when
`denote-prompts' is set to \\='(type title keywords)."
  (declare (interactive-only t))
  (interactive)
  (let ((denote-prompts '(type title keywords)))
    (call-interactively #'denote-open-or-create)))

;;;###autoload
(defun denote-open-or-create-with-subdirectory ()
  "Invoke `denote-open-or-create' but also prompt for subdirectory.
This is the equivalent to calling `denote-open-or-create' when
`denote-prompts' is set to \\='(subdirectory title keywords)."
  (declare (interactive-only t))
  (interactive)
  (let ((denote-prompts '(subdirectory title keywords)))
    (call-interactively #'denote-open-or-create)))

;;;###autoload
(defun denote-open-or-create-with-template ()
  "Invoke `denote-open-or-create' but also prompt for template.
This is the equivalent to calling `denote-open-or-create' when
`denote-prompts' is set to \\='(template title keywords).

For templates, refer to `denote-templates'."
  (declare (interactive-only t))
  (interactive)
  (let ((denote-prompts '(template title keywords)))
    (call-interactively #'denote-open-or-create)))
#+end_src

** Variants of ~denote-link-or-create~
:PROPERTIES:
:CUSTOM_ID: h:b6056e6b-93df-4e6b-a778-eebd105bac46
:END:

#+findex: denote-link-or-create
The command ~denote-link-or-create~ uses ~denote-link~ on a =TARGET=
file, creating it if necessary.  The =TARGET= matches the user input at
a minibuffer prompt: it is a file in the ~denote-directory~.

#+findex: denote-link-after-creating
If =TARGET= file does not exist, The ~denote-link-or-create~ calls
~denote-link-after-creating~ which runs the standard ~denote~ command
interactively to create the file ([[#h:6a92a8b5-d766-42cc-8e5b-8dc255466a23][Standard note creation]]).  The
established link will then be targeting that new file.

When called with an optional prefix argument (=C-u= by default)
~denote-link-or-create~ creates a link that consists of just the
identifier.  Else it tries to also include the file's title.  This has
the same meaning as in ~denote-link~ ([[#h:fc913d54-26c8-4c41-be86-999839e8ad31][Linking notes]]).

To speed up the process or to maintain variants that suit one's
workflow, we provide these ready-to-use commands that one can add to
their Emacs init file.  They can be assigned to key bindings or be used
via =M-x= after they have been evaluated.

#+begin_src emacs-lisp
;;;###autoload
(defun denote-link-or-create-with-date ()
  "Invoke `denote-link-or-create' but also prompt for date.

The date can be in YEAR-MONTH-DAY notation like 2022-06-30 or
that plus the time: 2022-06-16 14:30.  When the user option
`denote-date-prompt-use-org-read-date' is non-nil, the date
prompt uses the more powerful Org+calendar system.

This is the equivalent to calling `denote-link-or-create' when
`denote-prompts' is set to \\='(date title keywords)."
  (declare (interactive-only t))
  (interactive)
  (let ((denote-prompts '(date title keywords)))
    (call-interactively #'denote-link-or-create)))

;;;###autoload
(defun denote-link-or-create-with-type ()
  "Invoke `denote-link-or-create' but also prompt for file type.
This is the equivalent to calling `denote-link-or-create' when
`denote-prompts' is set to \\='(type title keywords)."
  (declare (interactive-only t))
  (interactive)
  (let ((denote-prompts '(type title keywords)))
    (call-interactively #'denote-link-or-create)))

;;;###autoload
(defun denote-link-or-create-with-subdirectory ()
  "Invoke `denote-link-or-create' but also prompt for subdirectory.
This is the equivalent to calling `denote-link-or-create' when
`denote-prompts' is set to \\='(subdirectory title keywords)."
  (declare (interactive-only t))
  (interactive)
  (let ((denote-prompts '(subdirectory title keywords)))
    (call-interactively #'denote-link-or-create)))

;;;###autoload
(defun denote-link-or-create-with-template ()
  "Invoke `denote-link-or-create' but also prompt for template.
This is the equivalent to calling `denote-link-or-create' when
`denote-prompts' is set to \\='(template title keywords).

For templates, refer to `denote-templates'."
  (declare (interactive-only t))
  (interactive)
  (let ((denote-prompts '(template title keywords)))
    (call-interactively #'denote-link-or-create)))
#+end_src

* Installation
:PROPERTIES:
:CUSTOM_ID: h:f3bdac2c-4704-4a51-948c-a789a2589790
:END:
#+cindex: Installation instructions

** GNU ELPA package
:PROPERTIES:
:CUSTOM_ID: h:42953f87-82bd-43ec-ab99-22b1e22955e7
:END:

The package is available as =denote=.  Simply do:

: M-x package-refresh-contents
: M-x package-install

And search for it.

GNU ELPA provides the latest stable release.  Those who prefer to follow
the development process in order to report bugs or suggest changes, can
use the version of the package from the GNU-devel ELPA archive.  Read:
https://protesilaos.com/codelog/2022-05-13-emacs-elpa-devel/.

** Manual installation
:PROPERTIES:
:CUSTOM_ID: h:d397712c-c8c0-4cfa-ad1a-ef28cf78d1f0
:END:

Assuming your Emacs files are found in =~/.emacs.d/=, execute the
following commands in a shell prompt:

#+begin_src sh
cd ~/.emacs.d

# Create a directory for manually-installed packages
mkdir manual-packages

# Go to the new directory
cd manual-packages

# Clone this repo, naming it "denote"
git clone https://git.sr.ht/~protesilaos/denote denote
#+end_src

Finally, in your =init.el= (or equivalent) evaluate this:

#+begin_src emacs-lisp
;; Make Elisp files in that directory available to the user.
(add-to-list 'load-path "~/.emacs.d/manual-packages/denote")
#+end_src

Everything is in place to set up the package.

* Sample configuration
:PROPERTIES:
:CUSTOM_ID: h:5d16932d-4f7b-493d-8e6a-e5c396b15fd6
:END:
#+cindex: Package configuration

#+begin_src emacs-lisp
(require 'denote)

;; Remember to check the doc strings of those variables.
(setq denote-directory (expand-file-name "~/Documents/notes/"))
(setq denote-known-keywords '("emacs" "philosophy" "politics" "economics"))
(setq denote-infer-keywords t)
(setq denote-sort-keywords t)
(setq denote-file-type nil) ; Org is the default, set others here
(setq denote-prompts '(title keywords))
(setq denote-excluded-directories-regexp nil)
(setq denote-excluded-keywords-regexp nil)

;; Pick dates, where relevant, with Org's advanced interface:
(setq denote-date-prompt-use-org-read-date t)


;; Read this manual for how to specify `denote-templates'.  We do not
;; include an example here to avoid potential confusion.


;; We allow multi-word keywords by default.  The author's personal
;; preference is for single-word keywords for a more rigid workflow.
(setq denote-allow-multi-word-keywords t)

(setq denote-date-format nil) ; read doc string

;; By default, we do not show the context of links.  We just display
;; file names.  This provides a more informative view.
(setq denote-backlinks-show-context t)

;; Also see `denote-link-backlinks-display-buffer-action' which is a bit
;; advanced.

;; If you use Markdown or plain text files (Org renders links as buttons
;; right away)
(add-hook 'find-file-hook #'denote-link-buttonize-buffer)

;; We use different ways to specify a path for demo purposes.
(setq denote-dired-directories
      (list denote-directory
            (thread-last denote-directory (expand-file-name "attachments"))
            (expand-file-name "~/Documents/books")))

;; Generic (great if you rename files Denote-style in lots of places):
;; (add-hook 'dired-mode-hook #'denote-dired-mode)
;;
;; OR if only want it in `denote-dired-directories':
(add-hook 'dired-mode-hook #'denote-dired-mode-in-directories)

;; Here is a custom, user-level command from one of the examples we
;; showed in this manual.  We define it here and add it to a key binding
;; below.
(defun my-denote-journal ()
  "Create an entry tagged 'journal', while prompting for a title."
  (interactive)
  (denote
   (denote--title-prompt)
   '("journal")))

;; Denote DOES NOT define any key bindings.  This is for the user to
;; decide.  For example:
(let ((map global-map))
  (define-key map (kbd "C-c n j") #'my-denote-journal) ; our custom command
  (define-key map (kbd "C-c n n") #'denote)
  (define-key map (kbd "C-c n N") #'denote-type)
  (define-key map (kbd "C-c n d") #'denote-date)
  (define-key map (kbd "C-c n s") #'denote-subdirectory)
  (define-key map (kbd "C-c n t") #'denote-template)
  ;; If you intend to use Denote with a variety of file types, it is
  ;; easier to bind the link-related commands to the `global-map', as
  ;; shown here.  Otherwise follow the same pattern for `org-mode-map',
  ;; `markdown-mode-map', and/or `text-mode-map'.
  (define-key map (kbd "C-c n i") #'denote-link) ; "insert" mnemonic
  (define-key map (kbd "C-c n I") #'denote-link-add-links)
  (define-key map (kbd "C-c n b") #'denote-link-backlinks)
  (define-key map (kbd "C-c n f f") #'denote-link-find-file)
  (define-key map (kbd "C-c n f b") #'denote-link-find-backlink)
  ;; Note that `denote-rename-file' can work from any context, not just
  ;; Dired bufffers.  That is why we bind it here to the `global-map'.
  (define-key map (kbd "C-c n r") #'denote-rename-file)
  (define-key map (kbd "C-c n R") #'denote-rename-file-using-front-matter))

;; Key bindings specifically for Dired.
(let ((map dired-mode-map))
  (define-key map (kbd "C-c C-d C-i") #'denote-link-dired-marked-notes)
  (define-key map (kbd "C-c C-d C-r") #'denote-dired-rename-marked-files)
  (define-key map (kbd "C-c C-d C-R") #'denote-dired-rename-marked-files-using-front-matter))

(with-eval-after-load 'org-capture
  (setq denote-org-capture-specifiers "%l\n%i\n%?")
  (add-to-list 'org-capture-templates
               '("n" "New note (with denote.el)" plain
                 (file denote-last-path)
                 #'denote-org-capture
                 :no-save t
                 :immediate-finish nil
                 :kill-buffer t
                 :jump-to-captured t)))

;; Also check the commands `denote-link-after-creating',
;; `denote-link-or-create'.  You may want to bind them to keys as well.
#+end_src

* For developers or advanced users
:PROPERTIES:
:CUSTOM_ID: h:c916d8c5-540a-409f-b780-6ccbd90e088e
:END:

Denote is in a stable state and can be relied upon as the basis for
custom extensions.  Further below is a list with the functions or
variables we provide for public usage.  Those are in addition to all
user options and commands that are already documented in the various
sections of this manual.

In this context "public" is any form with single hyphens in its symbol,
such as ~denote-directory-files~.  We expressly support those, meaning
that we consider them reliable and commit to documenting any changes in
their particularities (such as through ~make-obsolete~, a record in the
change log, a blog post on the maintainer's website, and the like).

By contradistinction, a "private" form is declared with two hyphens in
its symbol such as ~denote--file-extension~.  Do not use those as we
might change them without further notice.

#+vindex: denote-id-format
+ Variable ~denote-id-format~ :: Format of ID prefix of a note's
  filename.  The note's ID is derived from the date and time of its
  creation ([[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file-naming scheme]]).

#+vindex: denote-id-regexp
+ Variable ~denote-id-regexp~ :: Regular expression to match
  ~denote-id-format~.

#+vindex: denote-title-regexp
+ Variable ~denote-title-regexp~ :: Regular expression to match the
  TITLE field in a file name ([[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file-naming scheme]]).

#+vindex: denote-keywords-regexp
+ Variable ~denote-keywords-regexp~ :: Regular expression to match the
  KEYWORDS field in a file name ([[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file-naming scheme]]).

#+vindex: denote-excluded-punctuation-regexp
+ Variable ~denote-excluded-punctuation-regexp~ :: Punctionation that
  is removed from file names.  We consider those characters illegal
  for our purposes.

#+vindex: denote-excluded-punctuation-extra-regexp
+ Variable ~denote-excluded-punctuation-extra-regexp~ :: Additional
  punctuation that is removed from file names.  This variable is for
  advanced users who need to extend the ~denote-excluded-punctuation-regexp~.
  Once we have a better understanding of what we should be omitting,
  we will update things accordingly.

#+findex: denote-file-is-note-p
+ Function ~denote-file-is-note-p~ :: Return non-nil if =FILE= is an
  actual Denote note.  For our purposes, a note must not be a
  directory, must satisfy ~file-regular-p~, its path must be part of
  the variable ~denote-directory~, it must have a Denote identifier in
  its name, and use one of the extensions implied by
  ~denote-file-type~.

#+findex: denote-file-has-identifier-p
+ Function ~denote-file-has-identifier-p~ :: Return non-nil if =FILE=
  has a Denote identifier.

#+findex: denote-file-has-supported-extension-p
+ Function ~denote-file-has-supported-extension-p~ :: Return non-nil
  if =FILE= has supported extension.  Also account for the possibility
  of an added =.gpg= suffix. Supported extensions are those implied by
  ~denote-file-type~.

#+findex: denote-file-is-writable-and-supported-p
+ Function ~denote-file-is-writable-and-supported-p~ :: Return non-nil
  if =FILE= is writable and has supported extension.

#+findex: denote-keywords
+ Function ~denote-keywords~ :: Return appropriate list of keyword
  candidates.  If ~denote-infer-keywords~ is non-nil, infer keywords
  from existing notes and combine them into a list with
  ~denote-known-keywords~.  Else use only the latter set of keywords
  ([[#h:6a92a8b5-d766-42cc-8e5b-8dc255466a23][Standard note creation]]).

#+findex: denote-keywords-sort
+ Function ~denote-keywords-sort~ :: Sort =KEYWORDS= if
  ~denote-sort-keywords~ is non-nil.  =KEYWORDS= is a list of strings,
  per ~denote-keywords-prompt~.

#+findex: denote-directory
+ Function ~denote-directory~ :: Return path of the variable
  ~denote-directory~ as a proper directory, also because it accepts a
  directory-local value for what we internally refer to as "silos"
  ([[#h:15719799-a5ff-4e9a-9f10-4ca03ef8f6c5][Maintain separate directories for notes]]).

#+findex: denote-directory-files
+ Function ~denote-directory-files~ :: Return list of absolute file
  paths in variable ~denote-directory~.  Files only need to have an
  identifier.  The return value may thus include file types that are
  not implied by ~denote-file-type~. To limit the return value to text
  files, use the function ~denote-directory-text-only-files~.
  Remember that the ~denote-directory~ accepts a directory-local value
  ([[#h:15719799-a5ff-4e9a-9f10-4ca03ef8f6c5][Maintain separate directories for notes]]).

#+findex: denote-directory-text-only-files
+ Function ~denote-directory-text-only-files~ :: Return list of text
  files in variable ~denote-directory~.  Filter
  ~denote-directory-files~ using ~denote-file-is-note-p~.

#+findex: denote-directory-subdirectories
+ Function ~denote-directory-subdirectories~ :: Return list of
  subdirectories in variable ~denote-directory~. Omit dotfiles (such
  as .git) unconditionally.  Also exclude whatever matches
  ~denote-excluded-directories-regexp~.  Note that the
  ~denote-directory~ accepts a directory-local value for what we call
  "silos" ([[#h:15719799-a5ff-4e9a-9f10-4ca03ef8f6c5][Maintain separate directories for notes]]).

#+findex: denote-directory-files-matching-regexp
+ Function ~denote-directory-files-matching-regexp~ :: Return list of
  files matching =REGEXP= in ~denote-directory-files~.

#+findex: denote-file-name-relative-to-denote-directory
+ Function ~denote-file-name-relative-to-denote-directory~ :: Return
  name of =FILE= relative to the variable ~denote-directory~.  =FILE=
  must be an absolute path.

#+findex: denote-get-path-by-id
+ Function ~denote-get-path-by-id~ :: Return absolute path of =ID=
  string in ~denote-directory-files~.

#+findex: denote-barf-duplicate-id
+ Function ~denote-barf-duplicate-id~ :: Throw a ~user-error~ if
  =IDENTIFIER= already exists.

#+findex: denote-sluggify
+ Function ~denote-sluggify~ :: Make =STR= an appropriate slug for
  file names and related ([[#h:ae8b19a1-7f67-4258-96b3-370a72c43f4e][Sluggified title and keywords]]).

#+findex: denote-sluggify-and-join
+ Function ~denote-sluggify-and-join~ :: Sluggify =STR= while joining
  separate words.

#+findex: denote-desluggify
+ Function ~denote-desluggify~ :: Upcase first char in =STR= and
  dehyphenate =STR=, inverting ~denote-sluggify~.  Basically, convert
  =this-is-a-test= to =This is a test=.

#+findex: denote-sluggify-keywords
+ Function ~denote-sluggify-keywords~ :: Sluggify =KEYWORDS=, which is
  a list of strings ([[#h:ae8b19a1-7f67-4258-96b3-370a72c43f4e][Sluggified title and keywords]]).

#+findex: denote-filetype-heuristics
+ Function ~denote-filetype-heuristics~ :: Return likely file type of
  =FILE=.  Use the file extension to detect the file type of the file.

  If more than one file type correspond to this file extension, use the
  first file type for which the key-title-kegexp matches in the file or,
  if none matches, use the first type with this file extension in
  ~denote-file-type~.

  If no file types in ~denote-file-types~ has the file extension, the
  file type is assumed to be the first of ~denote-file-types~.

#+findex: denote-format-file-name
+ Function ~denote-format-file-name~ :: Format file name.  =PATH=,
  =ID=, =KEYWORDS=, =TITLE-SLUG= are expected to be supplied by
  ~denote~ or equivalent: they will all be converted into a single
  string.  =EXTENSION= is the file type extension, as a string.

#+findex: denote-extract-keywords-from-path
+ Function ~denote-extract-keywords-from-path~ :: Extract keywords
  from =PATH= and return them as a list of strings.  =PATH= must be a
  Denote-style file name where keywords are prefixed with an
  underscore.  If =PATH= has no such keywords, which is possible,
  return nil ([[#h:4e9c7512-84dc-4dfb-9fa9-e15d51178e5d][The file-naming scheme]]).

#+findex: denote-extract-id-from-string
+ Function ~denote-extract-id-from-string~ :: Return existing Denote
  identifier in =STRING=, else nil.

#+findex: denote-retrieve-filename-identifier
+ Function ~denote-retrieve-filename-identifier~ :: Extract identifier
  from =FILE= name.  To return an existing identifier or create a new
  one, refer to the ~denote-retrieve-or-create-file-identifier~
  function.

#+findex: denote-retrieve-or-create-file-identifier
+ Function ~denote-retrieve-or-create-file-identifier~ :: Return
  =FILE= identifier, generating one if appropriate.  The conditions
  are as follows:

  - If =FILE= has an identifier, return it.

  - If =FILE= does not have an identifier and optional =DATE= is
    non-nil, invoke ~denote-prompt-for-date-return-id~.

  - If =FILE= does not have an identifier and DATE is nil, use the
    file attributes to determine the last modified date and format it
    as an identifier.

  - As a fallback, derive an identifier from the current time.

  To only return an existing identifier, refer to the function
  ~denote-retrieve-filename-identifier~.

#+findex: denote-retrieve-filename-title
+ Function ~denote-retrieve-filename-title~ :: Extract title from
  =FILE= name, else return ~file-name-base~.  Run ~denote-desluggify~
  on the title if the extraction is successful.

#+findex: denote-retrieve-title-value
+ Function ~denote-retrieve-title-value~ :: Return title value from
  =FILE= front matter per =FILE-TYPE=.

#+findex: denote-retrieve-title-line
+ Function ~denote-retrieve-title-line~ :: Return title line from
  =FILE= front matter per =FILE-TYPE=.

#+findex: denote-retrieve-keywords-value
+ Function ~denote-retrieve-keywords-value~ :: Return keywords value
  from =FILE= front matter per =FILE-TYPE=.

#+findex: denote-retrieve-keywords-line
+ Function ~denote-retrieve-keywords-line~ :: Return keywords line
  from =FILE= front matter per =FILE-TYPE=.

#+findex: denote-file-prompt
+ Function ~denote-file-prompt~ :: Prompt for file with identifier in
  variable ~denote-directory~.  With optional =INITIAL-TEXT=, use it
  to prepopulate the minibuffer.

#+findex: denote-keywords-prompt
+ Function ~denote-keywords-prompt~ :: Prompt for one or more
  keywords.  In the case of multiple entries, those are separated by
  the ~crm-sepator~, which typically is a comma.  In such a scenario,
  the output is sorted with ~string-lessp~.  To sort the return value,
  use ~denote-keywords-sort~.

#+findex: denote-title-prompt
+ Function ~denote-title-prompt~ :: Read file title for ~denote~.
  With optional =DEFAULT-TITLE= use it as the default value.

#+findex: denote-file-type-prompt
+ Function ~denote-file-type-prompt~ :: Prompt for ~denote-file-type~.
  Note that a non-nil value other than ~text~, ~markdown-yaml~, and
  ~markdown-toml~ falls back to an Org file type.  We use ~org~ here
  for clarity.

#+findex: denote-date-prompt
+ Function ~denote-date-prompt~ :: Prompt for date, expecting
  =YYYY-MM-DD= or that plus =HH:MM= (or even =HH:MM:SS=).  Use Org's
  more advanced date selection utility if the user option
  ~denote-date-prompt-use-org-read-date~ is non-nil.  It requires Org
  ([[#h:e7ef08d6-af1b-4ab3-bb00-494a653e6d63][The denote-date-prompt-use-org-read-date option]]).

#+findex: denote-prompt-for-date-return-id
+ Function ~denote-prompt-for-date-return-id~ :: Use
  ~denote-date-prompt~ and return it as ~denote-id-format~.

#+findex: denote-template-prompt
+ Function ~denote-template-prompt~ :: Prompt for template key in
  ~denote-templates~ and return its value.

#+findex: denote-subdirectory-prompt
+ Function ~denote-subdirectory-prompt~ :: Prompt for subdirectory of
  the variable ~denote-directory~.  The table uses the ~file~
  completion category (so it works with packages such as ~marginalia~
  and ~embark~).

#+findex: denote-rename-file-prompt
+ Function ~denote-rename-file-prompt~ :: Prompt to rename file named
  =OLD-NAME= to =NEW-NAME=.

#+findex: denote-rename-file-and-buffer
+ Function ~denote-rename-file-and-buffer~ :: Rename file named
  =OLD-NAME= to =NEW-NAME=, updating buffer name.

#+findex: denote-update-dired-buffers
+ Function ~denote-update-dired-buffers~ :: Update Dired buffers of
  variable ~denote-directory~.  Note that the ~denote-directory~
  accepts a directory-local value for what we internally refer to as
  "silos" ([[#h:15719799-a5ff-4e9a-9f10-4ca03ef8f6c5][Maintain separate directories for notes]]).

#+vindex: denote-file-types
+ Variable ~denote-file-types~ :: Alist of ~denote-file-type~ and
  their format properties.

  Each element is of the form =(SYMBOL PROPERTY-LIST)=.  =SYMBOL= is
  one of those specified in ~denote-file-type~ or an arbitrary symbol
  that defines a new file type.

  =PROPERTY-LIST= is a plist that consists of eight elements:

  1. =:extension= is a string with the file extension including the
     period.

  2. =:date-function= is a function that can format a date.  See the
     functions ~denote--date-iso-8601~, ~denote--date-rfc3339~, and
     ~denote--date-org-timestamp~.

  3. =:front-matter= is either a string passed to ~format~ or a
     variable holding such a string.  The ~format~ function accepts
     four arguments, which come from ~denote~ in this order: =TITLE=,
     =DATE=, =KEYWORDS=, =IDENTIFIER=.  Read the doc string of
     ~format~ on how to reorder arguments.

  4. =:title-key-regexp= is a regular expression that is used to
     retrieve the title line in a file.  The first line matching this
     regexp is considered the title line.

  5. =:title-value-function= is the function used to format the raw
     title string for inclusion in the front matter (e.g. to surround
     it with quotes).  Use the ~identity~ function if no further
     processing is required.

  6. =:title-value-reverse-function= is the function used to retrieve
     the raw title string from the front matter.  It performs the
     reverse of =:title-value-function=.

  7. =:keywords-key-regexp= is a regular expression used to retrieve
     the keywords' line in the file.  The first line matching this
     regexp is considered the keywords' line.

  8. =:keywords-value-function= is the function used to format the
     keywords' list of strings as a single string, with appropriate
     delimiters, for inclusion in the front matter.

  9. =:keywords-value-reverse-function= is the function used to retrieve
     the keywords' value from the front matter.  It performs the reverse
     of the =:keywords-value-function=.

  10. =:link= is a string, or variable holding a string, that
      specifies the format of a link.  See the variables
      ~denote-org-link-format~, ~denote-md-link-format~.

  11. =:link-in-context-regexp= is a regular expression that is used
      to match the aforementioned link format.  See the variables
      ~denote-org-link-in-context-regexp~, ~denote-md-link-in-context-regexp~.

  If ~denote-file-type~ is nil, use the first element of this list for
  new note creation.  The default is ~org~.

#+vindex: denote-org-front-matter
+ Variable ~denote-org-front-matter~ :: Specifies the Org front
  matter.  It is passed to ~format~ with arguments =TITLE=, =DATE=,
  =KEYWORDS=, =ID= ([[#h:7f918854-5ed4-4139-821f-8ee9ba06ad15][Change the front matter format]])

#+vindex: denote-yaml-front-matter
+ Variable ~denote-yaml-front-matter~ :: Specifies the YAML (Markdown)
  front matter.  It is passed to ~format~ with arguments =TITLE=,
  =DATE=, =KEYWORDS=, =ID= ([[#h:7f918854-5ed4-4139-821f-8ee9ba06ad15][Change the front matter format]])

#+vindex: denote-toml-front-matter
+ Variable ~denote-toml-front-matter~ :: Specifies the TOML (Markdown)
  front matter.  It is passed to ~format~ with arguments =TITLE=,
  =DATE=, =KEYWORDS=, =ID= ([[#h:7f918854-5ed4-4139-821f-8ee9ba06ad15][Change the front matter format]])

#+vindex: denote-text-front-matter
+ Variable ~denote-text-front-matter~ :: Specifies the plain text
  front matter.  It is passed to ~format~ with arguments =TITLE=,
  =DATE=, =KEYWORDS=, =ID= ([[#h:7f918854-5ed4-4139-821f-8ee9ba06ad15][Change the front matter format]])

#+vindex: denote-org-link-format
+ Variable ~denote-org-link-format~ :: Format of Org link to note.
  The value is passed to ~format~ with =IDENTIFIER= and =TITLE=
  arguments, in this order.  Also see ~denote-org-link-in-context-regexp~.

#+vindex: denote-md-link-format
+ Variable ~denote-md-link-format~ :: Format of Markdown link to note.
  The =%N$s= notation used in the default value is for ~format~ as the
  supplied arguments are =IDENTIFIER= and =TITLE=, in this order.
  Also see ~denote-md-link-in-context-regexp~.

#+vindex: denote-id-only-link-format
+ Variable ~denote-id-only-link-format~ :: Format of identifier-only
  link to note.  The value is passed to ~format~ with =IDENTIFIER= as
  its sole argument.    Also see ~denote-id-only-link-in-context-regexp~.

#+vindex: denote-org-link-in-context-regexp
+ Variable ~denote-org-link-in-context-regexp~ :: Regexp to match an
  Org link in its context.  The format of such links is ~denote-org-link-format~.

#+vindex: denote-md-link-in-context-regexp
+ Variable ~denote-md-link-in-context-regexp~ :: Regexp to match an
  Markdown link in its context.  The format of such links is ~denote-md-link-format~.

#+vindex: denote-id-only-link-in-context-regexp
+ Variable ~denote-id-only-link-in-context-regexp~ :: Regexp to match
  an identifier-only link in its context.  The format of such links is
  ~denote-id-only-link-format~.

#+findex: denote-surround-with-quotes
+ Function ~denote-surround-with-quotes~ :: Surround string =S= with
  quotes.  This can be used in ~denote-file-types~ to format front
  mattter.

#+findex: denote-date-org-timestamp
+ Function ~denote-date-org-timestamp~ :: Format =DATE= using the Org
  inactive timestamp notation.

#+findex: denote-date-rfc3339
+ Function ~denote-date-rfc3339~ :: Format =DATE= using the RFC3339
  specification.

#+findex: denote-date-iso-8601
+ Function ~denote-date-iso-8601~ :: Format =DATE= according to ISO
  8601 standard.

#+findex: denote-trim-whitespace
+ Function ~denote-trim-whitespace~ :: Trim whitespace around string
  =S=.  This can be used in ~denote-file-types~ to format front
  mattter.

#+findex: denote-trim-whitespace-then-quotes
+ Function ~denote-trim-whitespace-then-quotes~ :: Trim whitespace
  then quotes around string =S=.  This can be used in
  ~denote-file-types~ to format front mattter.

#+findex: denote-format-keywords-for-md-front-matter
+ Function ~denote-format-keywords-for-md-front-matter~ :: Format
  front matter =KEYWORDS= for markdown file type.  =KEYWORDS= is a
  list of strings.  Consult the ~denote-file-types~ for how this is
  used.

#+findex: denote-format-keywords-for-text-front-matter
+ Function ~denote-format-keywords-for-text-front-matter~ :: Format
  front matter =KEYWORDS= for text file type.  =KEYWORDS= is a list of
  strings.  Consult the ~denote-file-types~ for how this is used.

#+findex: denote-format-keywords-for-org-front-matter
+ Function ~denote-format-keywords-for-org-front-matter~ :: Format
  front matter =KEYWORDS= for org file type.  =KEYWORDS= is a list of
  strings.  Consult the ~denote-file-types~ for how this is used.

#+findex: denote-extract-keywords-from-front-matter
+ Function ~denote-extract-keywords-from-front-matter~ :: Format front
  matter =KEYWORDS= for org file type.  =KEYWORDS= is a list of
  strings.  Consult the ~denote-file-types~ for how this is used.

* Contributing
:PROPERTIES:
:CUSTOM_ID: h:1ebe4865-c001-4747-a6f2-0fe45aad71cd
:END:

Denote is a GNU ELPA package.  As such, any significant change to the
code requires copyright assignment to the Free Software Foundation (more
below).

You do not need to be a programmer to contribute to this package.
Sharing an idea or describing a workflow is equally helpful, as it
teaches us something we may not know and might be able to cover either
by extending Denote or expanding this manual ([[#h:044a6a0f-e382-4013-8279-8bf4e64e73c0][Things to do]]).  If you
prefer to write a blog post, make sure you share it with us: we can add
a section herein referencing all such articles.  Everyone gets
acknowledged ([[#h:f8126820-3b59-49fa-bcc2-73bd60132bb9][Acknowledgements]]).  There is no such thing as an
"insignificant contribution"---they all matter.

+ Package name (GNU ELPA): =denote=
+ Official manual: <https://protesilaos.com/emacs/denote>
+ Change log: <https://protesilaos.com/emacs/denote-changelog>
+ Git repo on SourceHut: <https://git.sr.ht/~protesilaos/denote>
  - Mirrors:
    + GitHub: <https://github.com/protesilaos/denote>
    + GitLab: <https://gitlab.com/protesilaos/denote>
+ Mailing list: <https://lists.sr.ht/~protesilaos/denote>

If our public media are not suitable, you are welcome to contact me
(Protesilaos) in private: <https://protesilaos.com/contact>.

Copyright assignment is a prerequisite to sharing code.  It is a simple
process.  Check the request form below (please adapt it accordingly).
You must write an email to the address mentioned in the form and then
wait for the FSF to send you a legal agreement.  Sign the document and
file it back to them.  This could all happen via email and take about a
week.  You are encouraged to go through this process.  You only need to
do it once.  It will allow you to make contributions to Emacs in
general.

#+begin_example text
Please email the following information to assign@gnu.org, and we
will send you the assignment form for your past and future changes.

Please use your full legal name (in ASCII characters) as the subject
line of the message.

REQUEST: SEND FORM FOR PAST AND FUTURE CHANGES

[What is the name of the program or package you're contributing to?]

GNU Emacs

[Did you copy any files or text written by someone else in these changes?
Even if that material is free software, we need to know about it.]

Copied a few snippets from the same files I edited.  Their author,
Protesilaos Stavrou, has already assigned copyright to the Free Software
Foundation.

[Do you have an employer who might have a basis to claim to own
your changes?  Do you attend a school which might make such a claim?]


[For the copyright registration, what country are you a citizen of?]


[What year were you born?]


[Please write your email address here.]


[Please write your postal address here.]





[Which files have you changed so far, and which new files have you written
so far?]

#+end_example

* Things to do
:PROPERTIES:
:CUSTOM_ID: h:044a6a0f-e382-4013-8279-8bf4e64e73c0
:END:

Denote should work well for what is described in this manual.  Though we
can always do better.  This is a non-exhaustive list with some
low-priority ideas you may want to help with ([[#h:1ebe4865-c001-4747-a6f2-0fe45aad71cd][Contributing]]).

- Support mutually-exclusive sets of tags.  For example, a =home=
  keyword would preclude =work=.  Personally, I am not a fan of such
  arrangements as there may be a case where something applies to both
  ends of this prefigured binary.  Though we can think about it.

- Add command that expands the identifier in links to a full file name.
  This would be useful for some sort of "export" operation where the
  absolute file path is necessary and where the Denote linking mechanism
  is not available.  Though this could be handled by the exporter, by
  doing something like what ~denote-link-find-file~ does.

- Add command that rewrites full names in links, if they are invalid.
  This would complement the renaming mechanism.  Personally, I think old
  titles in links are not a problem, because they show you what was true
  at the time and are usually relevant to their context.  Again though,
  it is an option worth exploring.

- Ensure integration between =denote:= links and the =embark= package.
  The idea is to allow Embark to understand the Denote buttons are links
  to files and correctly infer the absolute path.  I am not sure what a
  user would want to do with this, but maybe there are some interesting
  possibilities.

You are welcome to suggest more ideas.  If they do not broaden the scope
of Denote, they can be added to denote.el.  Otherwise we might think of
extensions to the core package.

* Publications about Denote
:PROPERTIES:
:CUSTOM_ID: h:ca0c38f9-fa3e-4901-947e-1b589335781d
:END:

The Emacs community is putting Denote to great use.  This section
includes publications that show how people configure their note-taking
setup.  If you have a blog post, video, or configuration file about
Denote, feel welcome to tell us about it ([[#h:1ebe4865-c001-4747-a6f2-0fe45aad71cd][Contributing]]).

+ David Wilson (SystemCrafters): /Generating a Blog Site from Denote
  Entries/, 2022-09-09, <https://www.youtube.com/watch?v=5R7ad5xz5wo>.

+ David Wilson (SystemCrafters): /Trying Out Prot's Denote, an Org
  Roam Alternative?/, 2022-07-15, <https://www.youtube.com/watch?v=QcRY_rsX0yY>.

+ Jack Baty: /Keeping my Org Agenda updated based on Denote keywords/,
  2022-11-30, <https://baty.net/2022/keeping-my-org-agenda-updated>.

+ Jeremy Friesen: /Denote Emacs Configuration/, 2022-10-02,
  <https://takeonrules.com/2022/10/09/denote-emacs-configuration/>

+ Jeremy Friesen: /Exploring the Denote Emacs Package/, 2022-10-01,
  <https://takeonrules.com/2022/10/01/exploring-the-denote-emacs-package/>

+ Jeremy Friesen: /Migration Plan for Org-Roam Notes to Denote/,
  2022-10-02, <https://takeonrules.com/2022/10/02/migration-plan-for-org-roam-notes-to-denote/>

+ Jeremy Friesen: /Project Dispatch Menu with Org Mode Metadata,
  Denote, and Transient/, 2022-11-19,
  <https://takeonrules.com/2022/11/19/project-dispatch-menu-with-org-mode-metadata-denote-and-transient/>

+ Peter Prevos: /Simulating Text Files with R to Test the Emacs Denote
  Package/, 2022-07-28, <https://lucidmanager.org/productivity/testing-denote-package/>.

* Alternatives to Denote
:PROPERTIES:
:CUSTOM_ID: h:dbb51a1b-90b8-48e8-953c-e2fb3e36981e
:END:

What follows is a list of Emacs packages for note-taking.  I
(Protesilaos) have not used any of them, as I was manually applying my
file-naming scheme beforehand and by the time those packages were
available I was already hacking on the predecessor of Denote as a means
of learning Emacs Lisp (a package which I called "Unassuming Sidenotes
of Little Significance", aka "USLS" which is pronounced as "U-S-L-S" or
"useless").  As such, I cannot comment at length on the differences
between Denote and each of those packages, beside what I gather from
their documentation.

+ [[https://github.com/org-roam/org-roam][org-roam]] :: The de facto standard in the Emacs milieu---and rightly
  so!  It has a massive community, is featureful, and should be an
  excellent companion to anyone who is invested in the Org ecosystem
  and/or knows what "Roam" is (I don't).  It has been explained to me
  that Org Roam uses a database to store a cache about your notes.  It
  otherwise uses standard Org files.  The cache helps refer to the same
  node through aliases which can provide lots of options.  Personally, I
  follow a single-topic-per-note approach, so anything beyond that is
  overkill.  If the database is only for a cache, then maybe that has no
  downside, though I am careful with any kind of specialised program as
  it creates a dependency.  If you ask me about database software in
  particular, I have no idea how to use one, let alone debug it or
  retrieve data from it if something goes awry (I could learn, but that
  is beside the point).

+ [[https://github.com/localauthor/zk][zk (or zk.el)]] :: Reading its documentation makes me think that this is
  Denote's sibling---the two projects have a lot of things in common,
  including the preference to rely on plain files and standard tools.
  The core difference is that Denote has a strict file-naming scheme.
  Other differences in available features are, in principle, matters of
  style or circumstance: both packages can have them.  As its initials
  imply, ZK enables a zettelkasten-like workflow.  It does not enforce
  it though, letting the user adapt the method to their needs and
  requirements.

+ [[https://github.com/ymherklotz/emacs-zettelkasten][zettelkasten]] :: This is another one of Denote's relatives, at least
  insofar as the goal of simplicity is concerned.  The major difference
  is that according to its documentation "the name of the file that is
  created is just a unique ID".  This is not consistent with our
  file-naming scheme which is all about making sense of your files by
  their name alone and being able to visually parse a listing of them
  without any kind of specialised tool (e.g. =ls -l= or =ls -C= on the
  command-line from inside the ~denote-directory~ give you a
  human-readable set of files names, while =find * -maxdepth 0 -type f=
  is another approach).

+ [[https://github.com/EFLS/zetteldeft][zetteldeft]] :: This is a zettelkasten note-taking system built on top
  of the =deft= package.  Deft provides a search interface to a
  directory, in this case the one holding the user's =zetteldeft= notes.
  Denote has no such dependency and is not opinionated about how the
  user prefers to search/access their notes: use Dired, Grep, the
  =consult= package, or whatever else you already have set up for all
  things Emacs, not just your notes.

Searching through =M-x list-packages= for "zettel" brings up more
matches.  =zetteldesk= is an extension to Org Roam and, as such, I
cannot possibly know what Org Roam truly misses and what the added-value
of this package is.  =neuron-mode= builds on top of an external program
called =neuron=, which I have never used.

Searching for "note" gives us a few more results.  =notes-mode= has
precious little documentation and I cannot tell what it actually does
(as I said in my presentation for LibrePlanet 2022, inadequate docs are
a bug).  =side-notes= differs from what we try to do with Denote, as it
basically gives you the means to record your thoughts about some other
project you are working on and keep them on the side: so it and Denote
should not be mutually exclusive.

If I missed something, please let me know.

** Alternative ideas with Emacs and further reading
:PROPERTIES:
:CUSTOM_ID: h:188c0986-f2fa-444f-b493-5429356e75cf
:END:

This section covers blog posts from the Emacs community on the matter of
note-taking.  They may reference some of the packages covered in the
previous section or provide their custom code ([[#h:dbb51a1b-90b8-48e8-953c-e2fb3e36981e][Alternatives to Denote]]).
The list is unsorted.

+ José Antonio Ortega Ruiz (aka "jao") explains a note-taking method
  that is simple like Denote but differs in other ways.  An interesting
  approach overall: https://jao.io/blog/2022-06-19-simple-note-taking.html.

+ Jethro Kuan (the main =org-roam= developer) explains their note-taking
  techniques: https://jethrokuan.github.io/org-roam-guide/.  Good ideas
  all round, regardless of the package/code you choose to use.

[ Development note: help expand this list. ]

* Frequently Asked Questions
:PROPERTIES:
:CUSTOM_ID: h:da2944c6-cde6-4c65-8f2d-579305a159bb
:END:

I (Protesilaos) answer some questions I have received or might get.  It
is assumed that you have read the rest of this manual: I will not go
into the specifics of how Denote works.

** Why develop Denote when PACKAGE already exists?
:PROPERTIES:
:CUSTOM_ID: h:b875450a-ae22-4899-ac23-c10fa9c279bb
:END:

I wrote Denote because I was using a variant of Denote's file-naming
scheme before I was even an Emacs user (I switched to Emacs from
Tmux+Vim+CLI in the summer of 2019).  I was originally inspired by
Jekyll, the static site generator, which I started using for my website
in 2016 (was on WordPress before).  Jekyll's files follow the
=YYYY-MM-DD-TITLE.md= pattern.  I liked its efficiency relative to the
unstructured mess I had before.  Eventually, I started using that scheme
outside the confines of my website's source code.  Over time I refined
it and here we are.

Note-taking is something I take very seriously, as I am a prolific
writer (just check my website, which only reveals the tip of the
iceberg).  As such, I need a program that does exactly what I want and
which I know how to extend.  I originally tried to use Org capture
templates to create new files with a Denote-style file-naming scheme but
never managed to achieve it.  Maybe because ~org-capture~ has some
hard-coded assumptions or I simply am not competent enough to hack on
core Org facilities.  Whatever the case, an alternative was in order.

The existence of PACKAGE is never a good reason for me not to conduct my
own experiments for recreational, educational, or practical purposes.
When the question arises of "why not contribute to PACKAGE instead?" the
answer is that without me experimenting in the first place, I would lack
the skills for such a task.  Furthermore, contributing to another
package does not guarantee I get what I want in terms of workflow.

Whether you should use Denote or not is another matter altogether:
choose whatever you want.

** Why not rely exclusively on Org?
:PROPERTIES:
:CUSTOM_ID: h:b9831849-5c71-484e-b444-bac19cc13151
:END:

I think Org is one of Emacs' killer apps.  I also believe it is not the
right tool for every job.  When I write notes, I want to focus on
writing.  Nothing more.  I thus have no need for stuff like org-babel,
scheduling to-do items, clocking time, and so on.  The more "mental
dependencies" you add to your workflow, the heavier the burden you carry
and the less focused you are on the task at hand: there is always that
temptation to tweak the markup, tinker with some syntactic construct,
obsess about what ought to be irrelevant to writing as such.

In technical terms, I also am not fond of Org's code base (I understand
why it is the way it is---just commenting on the fact).  Ever tried to
read it?  You will routinely find functions that are tens-to-hundreds of
lines long and have all sorts of special casing.  As I am not a
programmer and only learnt to write Elisp through trial and error, I
have no confidence in my ability to make Org do what I want at that
level, hence =denote= instead of =org-denote= or something.

Perhaps the master programmer is one who can deal with complexity and
keep adding to it.  I am of the opposite view, as language---code
included---is at its communicative best when it is clear and accessible.

Make no mistake: I use Org for the agenda and also to write technical
documentation that needs to be exported to various formats, including
this very manual.

** Why care about Unix tools when you use Emacs?
:PROPERTIES:
:CUSTOM_ID: h:da1e2469-8f04-450b-a379-a854efa80a36
:END:

My notes form part of my longer-term storage.  I do not want to have to
rely on a special program to be able to read them or filter them.  Unix
is universal, at least as far as I am concerned.

Denote streamlines some tasks and makes things easier in general, which
is consistent with how Emacs provides a layer of interactivity on top of
Unix.  Still, Denote's utilities can, in principle, be implemented as
POSIX shell scripts (minus the Emacs-specific parts like fontification
in Dired or the buttonization of links).

Portability matters.  For example, in the future I might own a
smartphone, so I prefer not to require Emacs, Org, or some other
executable to access my files on the go.

Furthermore, I might want to share those files with someone.  If I make
Emacs a requirement, I am limiting my circle to a handful of relatively
advanced users.

Please don't misinterpret this: I am using Emacs full-time for my
computing and maintain a growing list of packages for it.  This is just
me thinking long-term.

** Why many small files instead of few large ones?
:PROPERTIES:
:CUSTOM_ID: h:7d2e7b8a-d484-4c1d-8688-17f70f242ad7
:END:

I have read that Org favours the latter method.  If true, I strongly
disagree with it because of the implicit dependency it introduces and
the way it favours machine-friendliness over human-readability in terms
of accessing information.  Notes are long-term storage.  I might want to
access them on (i) some device with limited features, (ii) print on
paper, (iii) share with another person who is not a tech wizard.

There are good arguments for few large files, but all either prioritize
machine-friendliness or presuppose the use of sophisticated tools like
Emacs+Org.

Good luck using =less= on a generic TTY to read a file with a zillion
words, headings, sub-headings, sub-sub-headings, property drawers, and
other constructs!  You will not get the otherwise wonderful folding of
headings the way you do in Emacs---do not take such features for
granted.

My point is that notes should be atomic to help the user---and
potentially the user's family, friends, acquaintances---make sense of
them in a wide range of scenaria.  The more program-agnostic your file
is, the better for you and/or everyone else you might share your
writings with.

Human-readability means that we optimize for what matters to us.  If (a)
you are the only one who will ever read your notes, (b) always have
access to good software like Emacs+Org, (c) do not care about printing
on paper, then Denote's model is not for you.  Maybe you need to tweak
some ~org-capture~ template to append a new entry to one mega file (I do
that for my Org agenda, by the way, as I explained before about using
the right tool for the job).

** Does Denote perform well at scale?
:PROPERTIES:
:CUSTOM_ID: h:863f812a-aac7-42ea-83b3-fbbdb58e08d7
:END:

Denote does not do anything fancy and has no special requirements: it
uses standard tools to accomplish ordinary tasks.  If Emacs can cope
with lots of files, then that is all you need to know: Denote will work.

To put this to the test, Peter Prevos is running simulations with R that
generate large volumes of notes.  You can read the technicalities here:
<https://lucidmanager.org/productivity/testing-denote-package/>.
Excerpt:

#+begin_quote
Using this code I generated ten thousands notes and used this to test
the Denote package to see it if works at a large scale. This tests shows
that Prot's approach is perfectly capable of working with thousands of
notes.
#+end_quote

Of course, we are always prepared to make refinements to the code, where
necessary, without compromising on the project's principles.

** I add TODOs to my notes; will many files slow down the Org agenda?
:PROPERTIES:
:CUSTOM_ID: h:63c2f8d4-79ed-4c55-b3ef-e048a05802c0
:END:

Yes, many files will slow down the agenda due to how that works.  Org
collects all files specified in the ~org-agenda-files~, searches through
their contents for timestamped entries, and then loops through all days
to determine where each entry belongs.  The more days and more files,
the longer it takes to build the agenda.  Doing this with potentially
hundreds of files will have a noticeable impact on performance.

This is not a deficiency of Denote.  It happens with generic Org files.
The way the agenda is built is heavily favoring the use of a single file
that holds all your timestamped entries (or at least a few such files).
Tens or hundreds of files are inefficient for this job.  Plus doing so
has the side-effect of making Emacs open all those files, which you
probably do not need.

If you want my opinion though, be more forceful with the separation of
concerns.  Decouple your knowledge base from your ephemeral to-do list:
Denote (and others) can be used for the former, while you let standard
Org work splendidly for the latter---that is what I do, anyway.

Org has a powerful linking facility, whether you use ~org-store-link~ or
do it via an ~org-capture~ template.  If you want a certain note to be
associated with a task, just store the task in a single =tasks.org= (or
however you name it) and link to the relevant context.

Do not mix your knowledge base with your to-do items.  If you need help
figuring out the specifics of this workflow, you are welcome to ask for
help in our relevant channels ([[#h:1ebe4865-c001-4747-a6f2-0fe45aad71cd][Contributing]]).

** I want to sort by last modified, why won't Denote let me?
:PROPERTIES:
:CUSTOM_ID: h:a7fd5e0a-78f7-434e-aa2e-e150479c16e2
:END:

Denote does not sort files and will not reinvent tools that handle such
functionality.  This is the job of the file manager or command-line
executable that lists files.

I encourage you to read the manpage of the =ls= executable.  It will
help you in general, while it applies to Emacs as well via Dired.  The
gist is that you can update the =ls= flags that Dired uses on-the-fly:
type =C-u M-x dired-sort-toggle-or-edit= (=C-u s= by default) and append
=--sort=time= at the prompt.  To reverse the order, add the =-r= flag.
The user option ~dired-listing-switches~ sets your default preference.

There is also "virtual Dired" if you need something that cannot be
done with Dired ([[#h:d35d8d41-f51b-4139-af8f-9c8cc508e35b][Use dired-virtual-mode for arbitrary file listings]]).

** How do you handle the last modified case?
:PROPERTIES:
:CUSTOM_ID: h:764b5e87-cd22-4937-b5fc-af3892d6b3d8
:END:

Denote does not insert any meta data or heading pertaining to edits in
the file.  I am of the view that these either do not scale well or are
not descriptive enough.  Suppose you use a "lastmod" heading with a
timestamp: which lines where edited and what did the change amount to?

This is where an external program can be helpful.  Use a Version Control
System, such as Git, to keep track of all your notes.  Every time you
add a new file, record the addition.  Same for post-creation edits.
Your VCS will let you review the history of those changes.  For
instance, Emacs' built-in version control framework has a command that
produces a log of changes for the current file: =M-x vc-print-log=,
bound to =C-x v l= by default.  From there one can access the
corresponding diff output (use =M-x describe-mode= (=C-h m=) in an
unfamiliar buffer to learn more about it).  With Git in particular,
Emacs users have the option of the all-round excellent =magit= package.

In short: let Denote (or equivalent) create notes and link between them,
the file manager organise and provide access to files, search programs
deal with searching and narrowing, and version control software handle
the tracking of changes.

** Speed up backlinks' buffer creation?
:PROPERTIES:
:CUSTOM_ID: h:893eec49-d7be-4603-bcff-fcc247244011
:END:

Denotes leverages the built-in =xref= library to search for the
identifier of the current file and return any links to it.  For users
of Emacs version 28 or higher, there exists a user option to specify
the program that performs this search: ~xref-search-program~.  The
default is =grep=, which can be slow, though one may opt for =ugrep=,
=ripgrep=, or even specify something else (read the doc string of that
user option for the details).

Try either for these for better results:

#+begin_src emacs-lisp
(setq xref-search-program 'ripgrep)

;; OR

(setq xref-search-program 'ugrep)
#+end_src

To use whatever executable is available on your system, use something
like this:

#+begin_src emacs-lisp
;; Prefer ripgrep, then ugrep, and fall back to regular grep.
(setq xref-search-program
      (cond
       ((or (executable-find "ripgrep")
            (executable-find "rg"))
        'ripgrep)
       ((executable-find "ugrep")
        'ugrep)
       (t
        'grep)))
#+end_src

** Why do I get "Search failed with status 1" when I search for backlinks?
:PROPERTIES:
:CUSTOM_ID: h:42f6b07e-5956-469a-8294-17f9cf62eb2b
:END:

Denote uses [[info:emacs#Xref][Emacs' Xref]] to find backlinks.  Xref requires ~xargs~ and
one of ~grep~ or ~ripgrep~, depending on your configuration.

This is usually not an issue on *nix systems, but the necessary
executables are not available on Windows Emacs distributions.  Please
ensure that you have both ~xargs~ and either ~grep~ or ~ripgrep~
available within your ~PATH~ environment variable.

If you have ~git~ on Windows installed, then you may use the following
code (adjust the git's installation path if necessary):
#+begin_src emacs-lisp
  (setenv "PATH" (concat (getenv "PATH") ";" "C:\\Program Files\\Git\\usr\\bin"))
#+end_src

* Acknowledgements
:PROPERTIES:
:CUSTOM_ID: h:f8126820-3b59-49fa-bcc2-73bd60132bb9
:END:
#+cindex: Contributors

Denote is meant to be a collective effort.  Every bit of help matters.

+ Author/maintainer :: Protesilaos Stavrou.

+ Contributions to code or the manual :: Abin Simon, Alan Schmitt,
  Benjamin Kästner, Charanjit Singh, Clemens Radermacher, Colin
  McLear, Damien Cassou, Elias Storms, Eshel Yaron, Florian, Graham
  Marlow, Hilde Rhyne, Jack Baty, Jean-Philippe Gagné Guay, Jürgen
  Hötzel, Kaushal Modi, Kyle Meyer, Marc Fargas, Noboru Ota (nobiot),
  Peter Prevos, Philip Kaludercic, Quiliro Ordóñez, Stefan Monnier,
  Thibaut Benjamin.

+ Ideas and/or user feedback :: Abin Simon, Alan Schmitt, Alfredo
  Borrás, Benjamin Kästner, Colin McLear, Damien Cassou, Elias Storms,
  Federico Stilman, Florian, Frank Ehmsen, Guo Yong, Hanspeter Gisler,
  Jack Baty, Jeremy Friesen, Juanjo Presa, Johan Bolmsjö, Kaushal
  Modi, M. Hadi Timachi, Paul van Gelder, Peter Prevos, Shreyas
  Ragavan, Stefan Thesing, Summer Emacs, Sven Seebeck, Taoufik, Viktor
  Haag, Yi Liu, Ypot, atanasj, hpgisler, pRot0ta1p, sienic, sundar bp.

Special thanks to Peter Povinec who helped refine the file-naming
scheme, which is the cornerstone of this project.

Special thanks to Jean-Philippe Gagné Guay for the numerous
contributions to the code base.

* GNU Free Documentation License
:PROPERTIES:
:APPENDIX: t
:CUSTOM_ID: h:2d84e73e-c143-43b5-b388-a6765da974ea
:END:

#+texinfo: @include doclicense.texi

#+begin_export html
<pre>

                GNU Free Documentation License
                 Version 1.3, 3 November 2008


 Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
     <https://fsf.org/>
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

0. PREAMBLE

The purpose of this License is to make a manual, textbook, or other
functional and useful document "free" in the sense of freedom: to
assure everyone the effective freedom to copy and redistribute it,
with or without modifying it, either commercially or noncommercially.
Secondarily, this License preserves for the author and publisher a way
to get credit for their work, while not being considered responsible
for modifications made by others.

This License is a kind of "copyleft", which means that derivative
works of the document must themselves be free in the same sense.  It
complements the GNU General Public License, which is a copyleft
license designed for free software.

We have designed this License in order to use it for manuals for free
software, because free software needs free documentation: a free
program should come with manuals providing the same freedoms that the
software does.  But this License is not limited to software manuals;
it can be used for any textual work, regardless of subject matter or
whether it is published as a printed book.  We recommend this License
principally for works whose purpose is instruction or reference.


1. APPLICABILITY AND DEFINITIONS

This License applies to any manual or other work, in any medium, that
contains a notice placed by the copyright holder saying it can be
distributed under the terms of this License.  Such a notice grants a
world-wide, royalty-free license, unlimited in duration, to use that
work under the conditions stated herein.  The "Document", below,
refers to any such manual or work.  Any member of the public is a
licensee, and is addressed as "you".  You accept the license if you
copy, modify or distribute the work in a way requiring permission
under copyright law.

A "Modified Version" of the Document means any work containing the
Document or a portion of it, either copied verbatim, or with
modifications and/or translated into another language.

A "Secondary Section" is a named appendix or a front-matter section of
the Document that deals exclusively with the relationship of the
publishers or authors of the Document to the Document's overall
subject (or to related matters) and contains nothing that could fall
directly within that overall subject.  (Thus, if the Document is in
part a textbook of mathematics, a Secondary Section may not explain
any mathematics.)  The relationship could be a matter of historical
connection with the subject or with related matters, or of legal,
commercial, philosophical, ethical or political position regarding
them.

The "Invariant Sections" are certain Secondary Sections whose titles
are designated, as being those of Invariant Sections, in the notice
that says that the Document is released under this License.  If a
section does not fit the above definition of Secondary then it is not
allowed to be designated as Invariant.  The Document may contain zero
Invariant Sections.  If the Document does not identify any Invariant
Sections then there are none.

The "Cover Texts" are certain short passages of text that are listed,
as Front-Cover Texts or Back-Cover Texts, in the notice that says that
the Document is released under this License.  A Front-Cover Text may
be at most 5 words, and a Back-Cover Text may be at most 25 words.

A "Transparent" copy of the Document means a machine-readable copy,
represented in a format whose specification is available to the
general public, that is suitable for revising the document
straightforwardly with generic text editors or (for images composed of
pixels) generic paint programs or (for drawings) some widely available
drawing editor, and that is suitable for input to text formatters or
for automatic translation to a variety of formats suitable for input
to text formatters.  A copy made in an otherwise Transparent file
format whose markup, or absence of markup, has been arranged to thwart
or discourage subsequent modification by readers is not Transparent.
An image format is not Transparent if used for any substantial amount
of text.  A copy that is not "Transparent" is called "Opaque".

Examples of suitable formats for Transparent copies include plain
ASCII without markup, Texinfo input format, LaTeX input format, SGML
or XML using a publicly available DTD, and standard-conforming simple
HTML, PostScript or PDF designed for human modification.  Examples of
transparent image formats include PNG, XCF and JPG.  Opaque formats
include proprietary formats that can be read and edited only by
proprietary word processors, SGML or XML for which the DTD and/or
processing tools are not generally available, and the
machine-generated HTML, PostScript or PDF produced by some word
processors for output purposes only.

The "Title Page" means, for a printed book, the title page itself,
plus such following pages as are needed to hold, legibly, the material
this License requires to appear in the title page.  For works in
formats which do not have any title page as such, "Title Page" means
the text near the most prominent appearance of the work's title,
preceding the beginning of the body of the text.

The "publisher" means any person or entity that distributes copies of
the Document to the public.

A section "Entitled XYZ" means a named subunit of the Document whose
title either is precisely XYZ or contains XYZ in parentheses following
text that translates XYZ in another language.  (Here XYZ stands for a
specific section name mentioned below, such as "Acknowledgements",
"Dedications", "Endorsements", or "History".)  To "Preserve the Title"
of such a section when you modify the Document means that it remains a
section "Entitled XYZ" according to this definition.

The Document may include Warranty Disclaimers next to the notice which
states that this License applies to the Document.  These Warranty
Disclaimers are considered to be included by reference in this
License, but only as regards disclaiming warranties: any other
implication that these Warranty Disclaimers may have is void and has
no effect on the meaning of this License.

2. VERBATIM COPYING

You may copy and distribute the Document in any medium, either
commercially or noncommercially, provided that this License, the
copyright notices, and the license notice saying this License applies
to the Document are reproduced in all copies, and that you add no
other conditions whatsoever to those of this License.  You may not use
technical measures to obstruct or control the reading or further
copying of the copies you make or distribute.  However, you may accept
compensation in exchange for copies.  If you distribute a large enough
number of copies you must also follow the conditions in section 3.

You may also lend copies, under the same conditions stated above, and
you may publicly display copies.


3. COPYING IN QUANTITY

If you publish printed copies (or copies in media that commonly have
printed covers) of the Document, numbering more than 100, and the
Document's license notice requires Cover Texts, you must enclose the
copies in covers that carry, clearly and legibly, all these Cover
Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on
the back cover.  Both covers must also clearly and legibly identify
you as the publisher of these copies.  The front cover must present
the full title with all words of the title equally prominent and
visible.  You may add other material on the covers in addition.
Copying with changes limited to the covers, as long as they preserve
the title of the Document and satisfy these conditions, can be treated
as verbatim copying in other respects.

If the required texts for either cover are too voluminous to fit
legibly, you should put the first ones listed (as many as fit
reasonably) on the actual cover, and continue the rest onto adjacent
pages.

If you publish or distribute Opaque copies of the Document numbering
more than 100, you must either include a machine-readable Transparent
copy along with each Opaque copy, or state in or with each Opaque copy
a computer-network location from which the general network-using
public has access to download using public-standard network protocols
a complete Transparent copy of the Document, free of added material.
If you use the latter option, you must take reasonably prudent steps,
when you begin distribution of Opaque copies in quantity, to ensure
that this Transparent copy will remain thus accessible at the stated
location until at least one year after the last time you distribute an
Opaque copy (directly or through your agents or retailers) of that
edition to the public.

It is requested, but not required, that you contact the authors of the
Document well before redistributing any large number of copies, to
give them a chance to provide you with an updated version of the
Document.


4. MODIFICATIONS

You may copy and distribute a Modified Version of the Document under
the conditions of sections 2 and 3 above, provided that you release
the Modified Version under precisely this License, with the Modified
Version filling the role of the Document, thus licensing distribution
and modification of the Modified Version to whoever possesses a copy
of it.  In addition, you must do these things in the Modified Version:

A. Use in the Title Page (and on the covers, if any) a title distinct
   from that of the Document, and from those of previous versions
   (which should, if there were any, be listed in the History section
   of the Document).  You may use the same title as a previous version
   if the original publisher of that version gives permission.
B. List on the Title Page, as authors, one or more persons or entities
   responsible for authorship of the modifications in the Modified
   Version, together with at least five of the principal authors of the
   Document (all of its principal authors, if it has fewer than five),
   unless they release you from this requirement.
C. State on the Title page the name of the publisher of the
   Modified Version, as the publisher.
D. Preserve all the copyright notices of the Document.
E. Add an appropriate copyright notice for your modifications
   adjacent to the other copyright notices.
F. Include, immediately after the copyright notices, a license notice
   giving the public permission to use the Modified Version under the
   terms of this License, in the form shown in the Addendum below.
G. Preserve in that license notice the full lists of Invariant Sections
   and required Cover Texts given in the Document's license notice.
H. Include an unaltered copy of this License.
I. Preserve the section Entitled "History", Preserve its Title, and add
   to it an item stating at least the title, year, new authors, and
   publisher of the Modified Version as given on the Title Page.  If
   there is no section Entitled "History" in the Document, create one
   stating the title, year, authors, and publisher of the Document as
   given on its Title Page, then add an item describing the Modified
   Version as stated in the previous sentence.
J. Preserve the network location, if any, given in the Document for
   public access to a Transparent copy of the Document, and likewise
   the network locations given in the Document for previous versions
   it was based on.  These may be placed in the "History" section.
   You may omit a network location for a work that was published at
   least four years before the Document itself, or if the original
   publisher of the version it refers to gives permission.
K. For any section Entitled "Acknowledgements" or "Dedications",
   Preserve the Title of the section, and preserve in the section all
   the substance and tone of each of the contributor acknowledgements
   and/or dedications given therein.
L. Preserve all the Invariant Sections of the Document,
   unaltered in their text and in their titles.  Section numbers
   or the equivalent are not considered part of the section titles.
M. Delete any section Entitled "Endorsements".  Such a section
   may not be included in the Modified Version.
N. Do not retitle any existing section to be Entitled "Endorsements"
   or to conflict in title with any Invariant Section.
O. Preserve any Warranty Disclaimers.

If the Modified Version includes new front-matter sections or
appendices that qualify as Secondary Sections and contain no material
copied from the Document, you may at your option designate some or all
of these sections as invariant.  To do this, add their titles to the
list of Invariant Sections in the Modified Version's license notice.
These titles must be distinct from any other section titles.

You may add a section Entitled "Endorsements", provided it contains
nothing but endorsements of your Modified Version by various
parties--for example, statements of peer review or that the text has
been approved by an organization as the authoritative definition of a
standard.

You may add a passage of up to five words as a Front-Cover Text, and a
passage of up to 25 words as a Back-Cover Text, to the end of the list
of Cover Texts in the Modified Version.  Only one passage of
Front-Cover Text and one of Back-Cover Text may be added by (or
through arrangements made by) any one entity.  If the Document already
includes a cover text for the same cover, previously added by you or
by arrangement made by the same entity you are acting on behalf of,
you may not add another; but you may replace the old one, on explicit
permission from the previous publisher that added the old one.

The author(s) and publisher(s) of the Document do not by this License
give permission to use their names for publicity for or to assert or
imply endorsement of any Modified Version.


5. COMBINING DOCUMENTS

You may combine the Document with other documents released under this
License, under the terms defined in section 4 above for modified
versions, provided that you include in the combination all of the
Invariant Sections of all of the original documents, unmodified, and
list them all as Invariant Sections of your combined work in its
license notice, and that you preserve all their Warranty Disclaimers.

The combined work need only contain one copy of this License, and
multiple identical Invariant Sections may be replaced with a single
copy.  If there are multiple Invariant Sections with the same name but
different contents, make the title of each such section unique by
adding at the end of it, in parentheses, the name of the original
author or publisher of that section if known, or else a unique number.
Make the same adjustment to the section titles in the list of
Invariant Sections in the license notice of the combined work.

In the combination, you must combine any sections Entitled "History"
in the various original documents, forming one section Entitled
"History"; likewise combine any sections Entitled "Acknowledgements",
and any sections Entitled "Dedications".  You must delete all sections
Entitled "Endorsements".


6. COLLECTIONS OF DOCUMENTS

You may make a collection consisting of the Document and other
documents released under this License, and replace the individual
copies of this License in the various documents with a single copy
that is included in the collection, provided that you follow the rules
of this License for verbatim copying of each of the documents in all
other respects.

You may extract a single document from such a collection, and
distribute it individually under this License, provided you insert a
copy of this License into the extracted document, and follow this
License in all other respects regarding verbatim copying of that
document.


7. AGGREGATION WITH INDEPENDENT WORKS

A compilation of the Document or its derivatives with other separate
and independent documents or works, in or on a volume of a storage or
distribution medium, is called an "aggregate" if the copyright
resulting from the compilation is not used to limit the legal rights
of the compilation's users beyond what the individual works permit.
When the Document is included in an aggregate, this License does not
apply to the other works in the aggregate which are not themselves
derivative works of the Document.

If the Cover Text requirement of section 3 is applicable to these
copies of the Document, then if the Document is less than one half of
the entire aggregate, the Document's Cover Texts may be placed on
covers that bracket the Document within the aggregate, or the
electronic equivalent of covers if the Document is in electronic form.
Otherwise they must appear on printed covers that bracket the whole
aggregate.


8. TRANSLATION

Translation is considered a kind of modification, so you may
distribute translations of the Document under the terms of section 4.
Replacing Invariant Sections with translations requires special
permission from their copyright holders, but you may include
translations of some or all Invariant Sections in addition to the
original versions of these Invariant Sections.  You may include a
translation of this License, and all the license notices in the
Document, and any Warranty Disclaimers, provided that you also include
the original English version of this License and the original versions
of those notices and disclaimers.  In case of a disagreement between
the translation and the original version of this License or a notice
or disclaimer, the original version will prevail.

If a section in the Document is Entitled "Acknowledgements",
"Dedications", or "History", the requirement (section 4) to Preserve
its Title (section 1) will typically require changing the actual
title.


9. TERMINATION

You may not copy, modify, sublicense, or distribute the Document
except as expressly provided under this License.  Any attempt
otherwise to copy, modify, sublicense, or distribute it is void, and
will automatically terminate your rights under this License.

However, if you cease all violation of this License, then your license
from a particular copyright holder is reinstated (a) provisionally,
unless and until the copyright holder explicitly and finally
terminates your license, and (b) permanently, if the copyright holder
fails to notify you of the violation by some reasonable means prior to
60 days after the cessation.

Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from that
copyright holder, and you cure the violation prior to 30 days after
your receipt of the notice.

Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under
this License.  If your rights have been terminated and not permanently
reinstated, receipt of a copy of some or all of the same material does
not give you any rights to use it.


10. FUTURE REVISIONS OF THIS LICENSE

The Free Software Foundation may publish new, revised versions of the
GNU Free Documentation License from time to time.  Such new versions
will be similar in spirit to the present version, but may differ in
detail to address new problems or concerns.  See
https://www.gnu.org/licenses/.

Each version of the License is given a distinguishing version number.
If the Document specifies that a particular numbered version of this
License "or any later version" applies to it, you have the option of
following the terms and conditions either of that specified version or
of any later version that has been published (not as a draft) by the
Free Software Foundation.  If the Document does not specify a version
number of this License, you may choose any version ever published (not
as a draft) by the Free Software Foundation.  If the Document
specifies that a proxy can decide which future versions of this
License can be used, that proxy's public statement of acceptance of a
version permanently authorizes you to choose that version for the
Document.

11. RELICENSING

"Massive Multiauthor Collaboration Site" (or "MMC Site") means any
World Wide Web server that publishes copyrightable works and also
provides prominent facilities for anybody to edit those works.  A
public wiki that anybody can edit is an example of such a server.  A
"Massive Multiauthor Collaboration" (or "MMC") contained in the site
means any set of copyrightable works thus published on the MMC site.

"CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0
license published by Creative Commons Corporation, a not-for-profit
corporation with a principal place of business in San Francisco,
California, as well as future copyleft versions of that license
published by that same organization.

"Incorporate" means to publish or republish a Document, in whole or in
part, as part of another Document.

An MMC is "eligible for relicensing" if it is licensed under this
License, and if all works that were first published under this License
somewhere other than this MMC, and subsequently incorporated in whole or
in part into the MMC, (1) had no cover texts or invariant sections, and
(2) were thus incorporated prior to November 1, 2008.

The operator of an MMC Site may republish an MMC contained in the site
under CC-BY-SA on the same site at any time before August 1, 2009,
provided the MMC is eligible for relicensing.


ADDENDUM: How to use this License for your documents

To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and
license notices just after the title page:

    Copyright (c)  YEAR  YOUR NAME.
    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, no Front-Cover Texts, and no Back-Cover Texts.
    A copy of the license is included in the section entitled "GNU
    Free Documentation License".

If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
replace the "with...Texts." line with this:

    with the Invariant Sections being LIST THEIR TITLES, with the
    Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.

If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the
situation.

If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of
free software license, such as the GNU General Public License,
to permit their use in free software.
</pre>
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