#+title: denote-search: a simple search utility for Denote
#+author: Lucas Quintana
#+email: lmq10@protonmail.com
#+language: en
#+options: ':t toc:nil author:t email:t num:t
#+startup: content
#+macro: stable-version 1.0.3
#+macro: release-date 2025-03-02
#+export_file_name: denote-search.texi
#+texinfo_filename: denote-search.info
#+texinfo_dir_category: Emacs misc features
#+texinfo_dir_title: Denote Search: (denote-search)
#+texinfo_dir_desc: A simple search utility for Denote
#+texinfo_header: @set MAINTAINER Lucas Quintana
#+texinfo_header: @set MAINTAINEREMAIL @email{lmq10@protonmail.com}
#+texinfo_header: @set MAINTAINERCONTACT @uref{mailto:lmq10@protonmail.com,contact the maintainer}

#+texinfo: @insertcopying

This manual, written by Lucas Quintana, describes the customization
options for the Emacs package called ~denote-search~ (or
=denote-search.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}}}.

#+toc: headlines 8

* COPYING
:PROPERTIES:
:COPYING: t
:END:

Copyright (C) 2024-2025  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

This package provides a simple search utility for the excellent
~denote~ program, the simple-to-use, focused-in-scope, and effective
note-taking tool for Emacs (see [[info:denote#Top]]).

~denote-search~ allows you to search for a regular expression in the
contents of your notes.  Once the results are populated, you are
presented with a buffer from which you can refine the search (that is,
search in the matched files), jump to a certain file using imenu,
exclude certain files from the search, or search only certain files.
All commands provided by Xref are available as well (see
info:emacs#Xref).

~denote-search~ approach has several advantages over similar tools
(~consult-grep~, ~consult-notes~, ~grep~, and so on):

- It allows to search in the files matched by a previous search, which
  as far as I know is not possible with other similar packages.

- It allows to search in the files referenced in a region, with the
  command ~denote-search-files-referenced-in-region~.  That is great
  for metanotes, shell outputs of =ls=, and more.

- It also allows to search in marked Dired files, with the command
  ~denote-search-marked-dired-files~.

- It doesn't rely on the minibuffer to output results, and it thus
  doesn't need a completion stack in order to work (~helm~,
  ~vertico+consult~, etc.).

- In fact, ~denote-search~ doesn't rely on any external package other
  than Denote.

- Unlike ~grep~, it allows excluding (or including only) certain files
  on-demand, without command-line gimmicks.

- It uses pretty file titles by default (and can be customized to show
  keywords or basically any other information as well).

Furthermore, ~denote-search~ has a small and simple codebase.  It is
designed to do one thing and one thing only: to search in your notes.

* Motivation

I wrote ~denote-search~ because I needed a simple tool to search my
personal knowledge database, which of course is managed with Denote.
Available options, such as ~consult-notes~, almost always used the
minibuffer to display results.  Which is fine, it works, but it is
sort of annoying on small screens.  In fact, I hacked the first
version of ~denote-search~ on Emacs for Android, in a time where I
didn't have a laptop with me.  Don't take those things as granted,
trust me.

I was mainly inspired by Howm[fn:1], a really great note-taking tool,
also made for Emacs.  It has a life-changing approach to notes: it
doesn't matter where do you store your information as long as you can
retrieve it later.  "Write fragmentarily and read collectively", that
is.  Howm has thus powerful search facilities built-in, some of which
(filtering and excluding/including files) I reimplemented in
~denote-search~.  I'm very happy now ^_^

* Points of entry

#+findex: denote-search
The main point of entry of this package is the ~denote-search~
command.  This command will prompt for a string.  You should input a
valid regular expression, as understood by the tool which will
actually perform the search.  Which program that is depends on the
value of ~xref-search-program~, and its arguments are taken from
~xref-search-program-alist~.  Note that ~denote-search~ is really just
a wrapper for Xref, albeit an useful one, so anything related to the
actual search results is the matter (for bad or for good) of that
library and/or the program it calls.

Once the (synchronous) search is over, a new buffer populated with the
results, if any, will be made current.  On that buffer, the user will
be able to perform several potentially useful actions, including
filtering the output (see [[#filtering-the-search-results][filtering the search results]]) and searching
in the matched files (see [[#focused-search][focused search]]).

History is available when searching.  Press ~M-p~
(~previous-history-element~) to view past queries.

There are two additional commands that can start a search:
~denote-search-marked-dired-files~ and
~denote-search-files-referenced-in-region~.  They allow searching a
restricted subset of files and are described in the next sections.

** Searching in marked Dired files

#+findex: denote-search-marked-dired-files
The command ~denote-search-marked-dired-files~ acts just like
~denote-search~, but it restricts the search to the files marked in
current Dired buffer (see [[info:emacs#Marks vs Flags][Marks vs Flags]]).  This is useful if you only
want to search some files, though depending on the case maybe you'd
be better served by our built-in filtering capabilities; see
[[#filtering-the-search-results][filtering the search results]].

This works well in tandem with the Denote command ~denote-sort-dired~,
which produces a Dired buffer with files matching a regexp.  So,
generating that buffer and then pressing ~t~ (~dired-toggle-marks~)
will enable you to use ~denote-search-marked-dired-files~ to search on
those files.  Again, using the filtering functionality available for
the results buffer should suit you better, but you have options.

** Searching in files referenced in a region

#+findex: denote-search-files-referenced-in-region
The command ~denote-search-files-referenced-in-region~ may seem odd at
first, but it's probably the most useful one.  It allows you to search
in a set of notes referenced in a buffer.  What does that means?
Well, it means that any buffer can serve as the source for the set of
files to search for; you just need Denote IDs written somewhere, and
the command will recognize them as files and search in them.

But let's look at an example.  Probably, you already have a note with
a section that resembles this:

#+begin_src org
,* See also

- An amazing note
- Another amazing note
- Yet another amazing note
#+end_src

Those notes are links and are highlighted as such, so internally they look like this:

#+begin_src org
,* See also

- [[denote:20231205T202124][An amazing note]]
- [[denote:20230720T154224][Another amazing note]]
- [[denote:20230719T194132][Yet another amazing note]]
#+end_src

That ~20231205T202124~ bit is the Denote ID.  That's the only thing
our command needs to recognize a note.  So, you just need to select
the section (with the mouse or ~C-SPC~, whichever you like the most)
and call ~denote-search-files-referenced-in-region~.  It will prompt
for a regexp just like ~denote-search~, but it will only search the
files selected.

This is useful for searching in notes linked in Org dynamic blocks
(first mark the block with ~org-babel-mark-block~), or for searching
something in linked notes in general (first mark the whole buffer with
~mark-whole-buffer~, bound to ~C-x h~).

This works everywhere.  If you had notes with the exact same IDs as
the ones depicted previously, you could select them in this very same
Info buffer (assuming you are reading this in Emacs) and search
something in them right away.

As the Denote ID is included in file names, you can also use this
command on Dired, on a shell output of ls from ~async-shell-command~,
and so on.  It's on those cases where you can grasp how powerful the
Denote file-naming scheme is.

* Navigating the search results

To navigate the results buffer, you can use the standard Xref commands
(see [[info:emacs#Xref Commands][Xref Commands]]).  So, for instance, ~n~ moves you to the next hit
and displays it in another window, and ~p~ does the same for the
previous one.  ~N~ moves you to the next file, while ~P~ moves you to
the previous one.

Aside from that, ~denote-search~ by default enables
~outline-minor-mode~ in the results buffer, and so additional
facilities are available.  You can fold file matches with TAB
(~outline-cycle~), in a similar fashion as an Org tree.  You can also
navigate all the files using ~imenu~ or an enhanced front-end such as
~consult-imenu~.  ~consult-outline~ also works here.

You can press ~a~ (~outline-cycle-buffer~) to fold all files.  This
can give you a quick overlook of all the files that matched the
search.  If there are many, you can proceed to filter the output 
(see [[#filtering-the-search-results][filtering the search results]]).

Press ~l~ (~recenter-current-error~) to recenter current search focus
shown in the other window.  Press ~o~ (~delete-other-windows~) to
close other windows displayed in the frame.

* Filtering the search results
:PROPERTIES:
:CUSTOM_ID: filtering-the-search-results
:END:

#+findex: denote-search-exclude-files
On the results buffer, you can press ~x~
(~denote-search-exclude-files~) to exclude certain files from the
search.  The command will prompt for a regular expression.  Once
given, the last search query will be re-run, but excluding all the
files that match the regular expression given.  For instance, you can
input =_philosophy= to exclude all the notes with the "philosophy"
keyword.  Or you can input =-emacs= to exclude all the notes that have
"emacs" in their title.  Or you can input =org$= to exclude Org files.
And so on.

#+findex: denote-search-include-files
You can press ~i~ (~denote-search-only-include-files~) for the
opposite operation; it will prompt for a regular expression, and then
re-run the search, but only on the files matched by the regular
expression given.

These commands always act as if the files matched by the last search
were all the Denote files in existence.  This has a great advantage;
you can chain them in any way you want.  You can, for example, press
~i~ and input =_emacs=, and then press ~x~ and input =_philosophy=.
The resulting buffer will have all the notes which have the keyword
"emacs" but not the keyword "philosophy", and will then display the
matches for the search query you made originally only for those
specific files.  You can of course keep filtering further.

To "break the chain" and start a totally new search, you can simply
call ~denote-search~, which is bound to ~s~ in the results buffer for
convenience.

It's possible that you don't want to start a new search, but rather to
search something on the curated file list you got.  See [[#focused-search][focused search]].

#+findex: denote-search-exclude-files-with-keywords
#+findex: denote-search-only-include-files-with-keywords
Filtering by keywords is such a common operation that two special
commands exist just for that: ~X~
(~denote-search-exclude-files-with-keywords~) and ~I~
(~denote-search-only-include-files-with-keywords~).  They are
equivalent to calling its regular counterparts and issuing a word with
a leading underscore; however, they also offer completion for
available keywords (using ~denote-keywords~, so its actual behaviour
is governed by the variables ~denote-infer-keywords~ and
~denote-known-keywords~).  But the main advantage is that they allow
issuing multiple keywords at once, separated by commas (or whatever
the value of ~crm-separator~ is, which should be a comma).

History is available when filtering.  Press ~M-p~
(~previous-history-element~) to view past queries.  This history is
kept separately from that available when searching.  In the case of
keyword filtering, history is shared with other Denote keyword
prompts.

#+findex: denote-search-clean-all-filters
To get rid of all filters, just type ~G~
(~denote-search-clean-all-filters~).  This simply re-runs the last
search on the full set of Denote files.  Note that this differs from
~g~ (~revert-buffer~), which re-runs the last search on the same set
of files (i.e. with filters applied).

* Focused search
:PROPERTIES:
:CUSTOM_ID: focused-search
:END:

A "focused search" is a search which is run against a set of files
matched by a previous search.  There are many use-cases for this,
including searching for a note that you know has two or three very
specific words, probably on different lines.

#+findex: denote-search-refine
On the results buffer, press ~f~ (~denote-search-refine~) to start a
focused search.  The command will prompt for a regular expression.
Once given, it will be searched in the files matched by the last
search.  The buffer will be properly updated and will show the matches
found.

Note that this feature, combined with the filtering capabilities
offered by this package (see [[#filtering-the-search-results][filtering the search results]]), can be
very powerful.

Let's look at a complex example, which would be nearly impossible with
other tools: search for all the mentions of "quantum mechanics" in
notes with the "science" keyword, without the "personal" keyword, and
which mention "Maxwell" somewhere in the text. The procedure is as
follows:

- =M-x denote-search RET maxwell RET= [fn:3]
- =i _science RET=
- =x _personal RET=
- =f quantum mechanics RET=

There it is, a really complex task is done in four straightforward
steps.  And all without external and platform-specific programs such
as xapian!

* Editing files

~denote-search~ is designed only for finding information in your
knowledge database, not for changing it.  You can open the files (with
~RET~, ~n~ or otherwise) and edit them as usual.

There's a special editing feature offered by Xref, though.  You can
press ~r~ (~xref-query-replace-in-results~) to replace the search
query (naturally as a regular expression) in the files matched; the
interface is similar to that of ~query-replace-regexp~.  This works in
the files then displayed in the results buffer, so you can filter and
fine-grain as usual to come with the replace command you wish.  Maybe
replace all the occurences of "Vim" with "Emacs" in notes with the
keyword "programming" but not in notes with the keyword "personal",
and only in files which mention "GNU"?  The sky is the limit!

* Customization

Although ~denote-search~ is designed to be simple and require no
special configuration, some options are available.

** Format of headings

By default, ~denote-search~ uses the pretty title found in the
front-matter to format note headings in the results buffer.  This is
pleasent to the eye and shouldn't impact performance (the bottleneck
is always the search itself).

#+vindex: denote-search-format-heading-function
You can change how headings are formatted by customizing the
~denote-search-format-heading-function~ variable.  It must be set to a
function which takes a single argument, the file path, and returns the
desired string for the heading.

#+findex: denote-search-extract-title
#+vindex: denote-search-untitled-string
By default, ~denote-search-extract-title~ is used, which produces the
aforementioned behaviour.  If it fails to find a suitable title for a
note, it uses the value of ~denote-search-untitled-string~.  You can
customize that, as well.

#+findex: denote-search-format-heading-with-keywords
This package also offers an alternative function, called
~denote-search-format-heading-with-keywords~.  If used as the heading
formatter, it adds keywords to the file title.  This isn't the default
merely to not clutter the view, but many users may prefer it.

You can write custom functions to display pretty much everything you
want in the headings.  Just keep in mind that the function is called
for every single matched file, so for large collection of notes, it
can indeed impact performance if you use complex code.

** Other options

#+vindex: denote-search-buffer-name
You can customize the name of the buffer where results are put using
the variable ~denote-search-buffer-name~.

#+vindex: denote-search-help-string
By default, the results buffer has a header line which displays
information about the search and a short help string.  Once you know
the commands by heart, you can set the variable
~denote-search-help-string~ to nil or a void string to disable the
help.

* Working with silos

If silos (see [[info:denote#Maintain separate directory silos for notes][denote#Maintain separate directory silos for notes]]) are
set up correctly (that is, with a =.dir-locals.el= file that sets a
value for ~denote-directory~), then ~denote-search~ should correctly
search in the contents of the silo when inside of it, without
additional configuration.

* Installation

** GNU ELPA package

The package is available as denote-search. Simply do:

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

And search for it.

** VC installation

You can install the package from source by evaluating the following
code:

#+begin_src elisp
(package-vc-install
 '(denote-search
   :url "https://github.com/lmq-10/denote-search"
   :doc "README.org"))
#+end_src

Alternatively, you can use the :vc keyword from use-package.

** Manual installation
:PROPERTIES:
:CUSTOM_ID: manual-installation
: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-search"
git clone https://github.com/lmq-10/denote-search denote-search
#+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-search")
#+end_src

Everything is in place to set up the package.

* Sample configuration
:PROPERTIES:
:CUSTOM_ID: sample-configuration
:END:

#+begin_src elisp
(use-package denote-search
  :ensure t
  :bind
  ;; Customize keybindings to your liking
  (("C-c s s" . denote-search)
   ("C-c s d" . denote-search-marked-dired-files)
   ("C-c s r" . denote-search-files-referenced-in-region))
  :custom
  ;; Disable help string (set it once you learn the commands)
  ;; (denote-search-help-string "")
  ;; Display keywords in results buffer
  (denote-search-format-heading-function #'denote-search-format-heading-with-keywords))
#+end_src

* Troubleshooting

Fixes for some common issues.

** Search is slow

Search is not managed by ~denote-search~, but rather by ~xref~.  Check
the value of ~xref-search-program~.  Changing it to =ripgrep= (after
installing it of course) can improve the speed.

* Acknowledgements

~denote-search~, just like Denote itself, is meant to be a collective
effort.  Every bit of help matters.

+ Author/maintainer :: Lucas Quintana.

+ Contributions to code :: Grant Rettke, Philip Kaludercic.

If ~denote-search~ exists it's because Protesilaos Stavrou developed
the incredible Denote package.  Please consider donating to him.[fn:2]

I also want to thank Richard Stallman (creator of GNU Emacs), Po Lu
(who ported it to Android, allowing me to write the first version of
~denote-search~) and Hiraoka Kazuyuki (author of Howm, from which this
package borrows some ideas).  This wouldn't be possible without them,
either.

* GNU Free Documentation License
:PROPERTIES:
:APPENDIX: t
:END:

#+texinfo: @include doclicense.texi

#+begin_export html
<pre>

                GNU Free Documentation License
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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>
#+end_export

#+html: <!--

* Indices
:PROPERTIES:
:END:

** Function index
:PROPERTIES:
:INDEX: fn
:END:

** Variable index
:PROPERTIES:
:INDEX: vr
:END:

** Concept index
:PROPERTIES:
:INDEX: cp
:END:

#+html: -->

* Footnotes
[fn:3] You'll probably bind ~denote-search~ to something comfortable, see [[#sample-configuration][Sample configuration]]

[fn:1] https://kaorahi.github.io/howm/

[fn:2] https://protesilaos.com/donations/