denote: Simple notes with a strict file-naming scheme

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}}}. Note that the project is still in active development and THINGS MIGHT CHANGE IN BACKWARD-INCOMPATIBLE WAYS until we make the first stable release.

• Homepage: https://protesilaos.com/emacs/denote.

• Git repository: https://git.sr.ht/~protesilaos/denote.
• Mailing list: https://lists.sr.ht/~protesilaos/denote.

• COPYING
• Overview
• The file-naming scheme
  • Sluggified title and keywords
• Points of entry
• Front matter
  • Tweaking the front matter
• Linking notes
• Fontification in Dired
• Renaming non-notes
• Extending Denote
• Installation
  • COMMENT GNU ELPA package
  • Manual installation
• Sample configuration
• Acknowledgements
• GNU Free Documentation License
• Indices
  • Function index
  • Variable index
  • Concept index

COPYING

Copyright (C) 2022 Free Software Foundation, Inc.

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.”

Overview

Denote is a simple, yet effective note-taking tool for Emacs. It is based on the principle that notes must follow a predictable and descriptive file-naming scheme. The file name alone should offer a clear indication of what the note is about, without reference to any other metadata. Denote basically streamlines the creation of such files.

What Denote prioritizes with the enforcement of a strict file-naming scheme is portability. Notes can be accessed, filtered, and understood without Emacs or any other advanced tool for that matter (though Emacs, Org, and the like are excellent programs).

Denote only has a strong opinion about the file name. It otherwise is flexible and poses no constraints on the desired workflow. Denote has no mechanism to test for adherence to a given note-taking method, such as that of Zettelkasten (i.e. the contemporary digital equivalent of Niklas Luhmann's methodology). It is possible to employ such a method, though it is ultimately up to the user to apply the requisite rigor. What matters for our purposes is that Denote is not a zettelkasten implementation per se.

By default, Denote creates note files using the .org extension. However, Denote does not depend on org.el or any of its accoutrements and extensions. Users are given the option to change from Org to either Markdown (.md) or Plain Text (.txt), as explained further in the manual (search for denote-file-type).

"Denote" is the familiar word, though it also is a play on to the "note" concept. Plus, we can come up with acronyms (of dubious utility) like:

• Don't Ever Note Only The Ephemeral
• Denote Everything Neatly; Omit The Excesses

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

The file-naming scheme

Every note produced by Denote follows this pattern:

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, that 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.

The KEYWORDS field consists of one or more entries demarcated by a plus sign (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 an underscore. So when emacs_library appears in a file name, it is interpreted as a single keyword, whereas emacs+library are two distinct keywords.

The EXTENSION is the file type. By default, it is .org (org-mode) though the user option denote-file-type provides support for Markdown (.md which runs markdown-mode) and plain text (.txt via text-mode). Consult its doc string for the minutia.

Examples:

20220107T124941--plentiful-and-predictable-liquidity--economics.org
20220214T104945--git-patch-formatting--emacs+git.md
20220420T113805--this-is-a-test--three_word_keyword.txt

While files end in the .org extension by default, the Denote code base does not actually depend on org.el and/or its accoutrements.

Notes are stored as a flat list in the denote-directory (i.e. no subdirectories). The default path is ~/Documents/notes.

Sluggified title and keywords

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 only in the note's contents (Front matter).
• Keywords should not have spaces or other delimiters. If they do, they are converted into hyphens. Keywords are always downcased.

Points of entry

There are two ways to write a note with Denote: invoke the denote command or leverage the org-capture-templates by setting up a template which calls the function denote-org-capture.

In the first case, all that is needed is to run denote. It will first prompt for a title. Once it is supplied, the command will ask for keywords. The resulting note will have a file name as already explained (The file naming scheme).

The keyword 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).

Multiple keywords can be inserted by separating them with a comma (or whatever the value of the crm-indicator 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 denote command can also be called from Lisp, in which case it expects the TITLE and KEYWORDS arguments. The former is a string, the latter a list of strings.

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

(with-eval-after-load 'org-capture
  (require 'denote-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)))

[ In the future, we might develop Denote in ways which do not require such manual intervation. ]

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. After that, the process is the same as with invoking denote directly, namely: a prompt for a title followed by a prompt for keywords.

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). Due to the particular file-naming scheme of Denote, such specifiers 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:

(setq denote-org-capture-specifiers "%l\n%i\n%?")

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.

Front matter

Notes have their own "front matter". This is a block of data at the top of the file, 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 (denote-file-type is nil):

#+title:      This is a sample note
#+date:       2022-06-10
#+filetags:   denote  testing
#+identifier: 20220610T202537

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

---
title:      "This is a sample note"
date:       2022-06-10
tags:       denote  testing
identifier: "20220610T202021"
---

For Markdown with TOML, it looks like this (denote-file-type has the markdown-toml value):

+++
title      = "This is a sample note"
date       = 2022-06-10
tags       = ["denote", "testing"]
identifier = "20220610T201510"
+++

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

title:      This is a sample note
date:       2022-06-10
tags:       denote  testing
identifier: 20220610T202232
---------------------------

The format of the date in the front matter is controlled by the user option denote-front-matter-date-format:

• When the value is nil (the default), the date uses a plain YEAR-MONTH-DAY notation, like 2022-06-08 (the ISO 8601 standard).
• When the value is the org-timestamp symbol, the date is recorded as an inactive Org timestamp, such as [2022-06-08 Wed 06:19].
• An arbitrary string value is interpreted as the argument for the function format-time-string. This gives the user maximum control over how time is represented in the front matter.

When denote-file-type specifies one of the Markdown flavors, we ignore this user option in order to enforce the RFC3339 specification (Markdown is typically employed in static site generators as source code for Web pages). However, when denote-front-matter-date-format has a string value, this rule is suspended: we use whatever the user wants.

Tweaking the front matter

What follows is for advanced users. When in doubt, only configure variables we describe as a "user option": they are declared in the source code with the defcustom keyword.

Denote's code base is designed in a composable way, which lets the user make precise interventions to affect the output of the relevant commands. One such case is to configure the front matter, such as by changing the order the keys appear in, renaming them, or adding new elements.

Some examples are in order, starting with the Org file type. This is what we have in denote.el:

(defvar denote-org-front-matter
  "#+title:      %s
#+date:       %s
#+filetags:   %s
#+identifier: %s
\n"
  "Org front matter value for `format'.
The order of the arguments is TITLE, DATE, KEYWORDS, ID.  If you
are an avdanced user who wants to edit this variable to affect
how front matter is produced, consider using something like %2$s
to control where Nth argument is placed.")

The default front matter is:

#+title:      This is a sample note
#+date:       2022-06-10
#+filetags:   denote  testing
#+identifier: 20220610T202537

We can add a PROPERTIES drawer to it, with something like this:

(setq denote-org-front-matter
      ":PROPERTIES:
:ID: %4$s
:END:
#+title:      %1$s
#+date:       %2$s
#+filetags:   %3$s
#+identifier: %4$s
\n")

The output is now formatted thus:

:PROPERTIES:
:ID: 20220611T092444
:END:
#+title:      This is a sample note
#+date:       2022-06-11
#+filetags:   denote  testing
#+identifier: 20220611T092444

Notice how we can pass a number to the %s specifier. This is what allows us to change the placement of the provided arguments.

For another example, we will use the plain text variant, as it differs a bit from the above. By default it is formatted this way:

title:      This is a sample note
date:       2022-06-10
tags:       denote  testing
identifier: 20220610T202232
---------------------------

The line with the hyphens is documented in the product of the fifth format specifier, as documented in denote-text-front-matter. Its value is stored in denote-text-front-matter-delimiter. Say we want to have a delimiter both at the top and bottom:

(setq denote-text-front-matter
      "%5$s
title:      %1$s
date:       %2$s
tags:       %3$s
identifier: %4$s
%5$s\n\n")

Which gives us:

---------------------------
title:      This is a sample note
date:       2022-06-11
tags:       denote  testing
identifier: 20220611T093252
---------------------------

Or we would rather use another character instead of hyphens, such as the equals sign:

(setq denote-text-front-matter-delimiter (make-string 27 ?+))

Remember that this is for advanced users. If you want to see changes done on this front, you are welcome to share your thoughts and/or participate in the development of Denote.

Linking notes

Denote has a basic linking facility to quickly establish connections between notes. The command denote-link prompts for a file name in the denote-directory (only regular files are considered, not directories). It then retrieves the path of the given note, inserts it at point using the appropriate link notation, and creates a backlink entry in the target file (again using the appropriate notation).

What constitutes "appropriate link notation" depends on the file type of the given entry per denote-file-type (The file naming scheme). For example when linking from an Org file to a Markdown file, the link in the former will follow Org syntax while the backlink in the latter will use that of Markdown. Org links use [[file:TARGET][DESCRIPTION]], those of Markdown are [DESCRIPTION](file:TARGET), while for plain text we implement our own scheme of <TYPE: TARGET> [DESCRIPTION], where TYPE is either LINK or BACKLINK (capitalization in the latter two is literal, because plain text lacks other means of emphasis).

Plain text links can benefit from Emacs' notion of "future history", else its ability to read the thing at point for relevant commands. With point over the TARGET, M-x find-file followed by M-n will fill the path to that file (this also works with point over just the identifier of a note).

Backlinks are recorded at the end of a note under the heading with the title Denote backlinks. Users should not edit the note below this part manually: it is controlled by Denote, such as to delete duplicate links (in the future it might also handle stuff like alphabetic sorting).

The section with the backlinks is formatted according to the note's file type.

The special hook denote-link-insert-functions is called after a link is created. It accepts two arguments for the target file and the formatted backlink to the original file. The function denote-link-backlink provides an example for advanced users.

Backlinks that no longer point to available notes can be removed from the current buffer with the command denote-link-clear-stale-backlinks.

Fontification in Dired

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:

(require 'denote-dired)
(add-hook 'dired-mode-hook #'denote-dired-mode)

Or configure the user option denote-dired-directories and then set up the function denote-dired-mode-in-directories:

(require 'denote-dired)

;; 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)

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 (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).

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

Renaming non-notes

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

To this end, invoke denote-dired-rename-file when point is over a file in Dired to rename it. The commaand prompts for a TITLE and KEYWORDS the same way the denote command does it (Points of entry). It finally asks for confirmation before renaming the file at point.

The file type extension (e.g. .pdf) is read from the underlying file and is preserved in 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.

Extending Denote

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.

• To search through notes, use M-x grep, M-x find-name-dired, M-x consult-find, M-x consult-grep, and so on (the latter two are provided by the consult package).
• To quickly jump to the denote-directory, visit it with M-x find-file and then make a bookmark with M-x bookmark-set. Access bookmarks with M-x bookmark-jump, M-x consult-buffer (from consult), and the like.
• Control the versioning of notes by turning the denote-directory into a Git project. Consider the built-in project.el or the projectile package, as well as the built-in VC framework and/or the magit package.
• It is possible to narrow the list of notes in Dired using a regular expression or literal string. Do M-x dired-mark-files-regexp RET type-regexp-here RET t k. The t will toggle the match so that it marks all files that do not match the regexp and k will remove them from the buffer (restore them by reverting the buffer).
• A narrowed list of files can also be produced through the minibuffer, with the help of the embark package. For example, M-x find-file RET path/to/denote-directory RET regexp embark-act embark-export. The final two commands, embark-act and embark-export, are normally bound to keys. The whole sequence will thus look like C-x C-f path RET regexp C-. E.

Installation

COMMENT GNU ELPA package

The package is available as logos. 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

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

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

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

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

Everything is in place to set up the package.

Sample configuration

(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)

(setq denote-front-matter-date-format 'org-timestamp)

(require 'denote-link)
(require 'denote-dired)

;; 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")))

;; Generic:
;; (add-hook 'dired-mode-hook #'denote-dired-mode)
;;
;; OR better:
(add-hook 'dired-mode-hook #'denote-dired-mode-in-directories)

;; You can bind `denote' to a global key if you prefer not to use
;; `org-capture' or want an alternative.  For example:
(define-key global-map (kbd "C-c n") #'denote)

(with-eval-after-load 'org-capture
  (require 'denote-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))))

Acknowledgements

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

Author/maintainer

Protesilaos Stavrou.

Contributions to code or the manual

Jack Baty, Kaushal Modi.

Ideas and/or user feedback

Kaushal Modi, Ypot.

GNU Free Documentation License

                GNU Free Documentation License
                 Version 1.3, 3 November 2008


 Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
     
 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.