qubes-doc/developer/general/documentation-style-guide.md

---
lang: en
layout: doc
permalink: /doc/documentation-style-guide/
redirect_from:
- /doc/doc-guidelines/
- /en/doc/doc-guidelines/
- /wiki/DocStyle/
- /doc/DocStyle/
ref: 30
title: Documentation style guide
---

_Also see [how to edit the documentation](/doc/how-to-edit-the-documentation/)._

Qubes OS documentation pages are stored as plain text Markdown files in the
[qubes-doc](https://github.com/QubesOS/qubes-doc) repository. By cloning and
regularly pulling from this repo, users can maintain their own up-to-date
offline copy of all Qubes documentation rather than relying solely on the web.

The documentation is a volunteer community effort. People like you are
constantly working to make it better. If you notice something that can be fixed
or improved, please [edit the
documentation](/doc/how-to-edit-the-documentation/)!

This page explains the standards we follow for writing, formatting, and
organizing the documentation. Please follow these guidelines and conventions
when editing the documentation. For the standards governing the website as a
whole, please see the [website style guide](/doc/website-style-guide).

## Markdown conventions

All the documentation is written in Markdown for maximum accessibility. When
making contributions, please observe the following style conventions. If you're
not familiar with Markdown syntax,
[this](https://daringfireball.net/projects/markdown/) is a great resource.

### Hyperlink syntax

Use non-reference-style links like `[website](https://example.com/)`. Do *not*
use reference-style links like `[website][example]`, `[website][]` or
`[website]`. This facilitates the localization process.

### Relative vs. absolute links

Always use relative rather than absolute paths for internal website links. For
example, use `/doc/documentation-style-guide/` instead of
`https://www.qubes-os.org/doc/documentation-style-guide/`.

You may use absolute URLs in the following cases:

- External links
- URLs that appear inside code blocks (e.g., in comments and document
  templates, and the plain text reproductions of [QSBs](/security/qsb/) and
  [Canaries](/security/canary/)), since they're not hyperlinks
- Git repo files like `README.md` and `CONTRIBUTING.md`, since they're not part
  of the website itself but rather of the auxiliary infrastructure supporting
  the website

This rule is important because using absolute URLs for internal website links
breaks:

- Serving the website offline
- Website localization
- Generating offline documentation
- Automatically redirecting Tor Browser visitors to the correct page on the
  onion service mirror

### Image linking

See [how to add images](/doc/how-to-edit-the-documentation/#how-to-add-images)
for the required syntax. This will make the image a hyperlink to the image
file, allowing the reader to click on the image in order to view the full image
by itself. This is important. Following best practices, our website has a
responsive design, which allows the website to render appropriately across all
screen sizes. When viewing this page on a smaller screen, such as on a mobile
device, the image will automatically shrink down to fit the screen. If visitors
cannot click on the image to view it in full size, then, depending on their
device, they may have no way see the details in the image clearly.

In addition, make sure to link only to images in the
[qubes-attachment](https://github.com/QubesOS/qubes-attachment) repository. Do
not attempt to link to images hosted on other websites.

### HTML and CSS

Do not write HTML inside Markdown documents (except in rare, unavoidable cases,
such as alerts). In particular, never include HTML or CSS for styling,
formatting, or white space control. That belongs in the (S)CSS files instead.

### Headings

Do not use `h1` headings (single `#` or `======` underline). These are
automatically generated from the `title:` line in the YAML front matter.

Use Atx-style syntax for headings: `##h2`, `### h3`, etc. Do not use
underlining syntax (`-----`).

### Indentation

Use spaces instead of tabs. Use hanging indentations where appropriate.

### Lists

If appropriate, make numerals in numbered lists match between Markdown source
and HTML output. Some users read the Markdown source directly, and this makes
numbered lists easier to follow.

### Code blocks

When writing code blocks, use [syntax
highlighting](https://github.github.com/gfm/#info-string) where possible (see
[here](https://github.com/jneen/rouge/wiki/List-of-supported-languages-and-lexers)
for a list of supported languages). Use `[...]` for anything omitted.

### Line wrapping

Hard wrap Markdown lines at 80 characters, unless the line can't be broken
(e.g., code or a URL).

## Writing guidelines

### Correct use of terminology

Familiarize yourself with the terms defined in the [glossary](/doc/glossary/).
Use these terms consistently and accurately throughout your writing.

### Sentence case in headings

Use sentence case (rather than title case) in headings for the reasons
explained
[here](https://www.sallybagshaw.com.au/articles/sentence-case-v-title-case/).
In particular, since the authorship of the Qubes documentation is decentralized
and widely distributed among users from around the world, many contributors
come from regions with different conventions for implementing title case, not
to mention that there are often differing style guide recommendations even
within a single region. It is much easier for all of us to implement sentence
case consistently across our growing body of pages, which is very important for
managing the ongoing maintenance burden and sustainability of the
documentation.

### Writing command-line examples

When providing command-line examples:

- Tell the reader where to open a terminal (dom0 or a specific domU), and show
  the command along with its output (if any) in a code block, e.g.:

  ~~~markdown
  Open a terminal in dom0 and run:
  ```shell_session
  $ cd test
  $ echo Hello
  Hello
  ```
  ~~~

- Precede each command with the appropriate command prompt: At a minimum, the
  prompt should contain a trailing `#` (for the user `root`) or `$` (for other
  users) on Linux systems and `>` on Windows systems, respectively.

- Don't try to add comments inside the code block. For example, *don't* do
  this:

   ~~~markdown
   Open a terminal in dom0 and run:
   ```shell_session
   # Navigate to the new directory
   $ cd test
   # Generate a greeting
   $ echo Hello
   Hello
   ```
   ~~~

   The `#` symbol preceding each comment is ambiguous with a root command
   prompt. Instead, put your comments *outside* of the code block in normal
   prose.

### Variable names in commands

Syntactically distinguish variables in commands. For example, this is
ambiguous:

    $ qvm-run --dispvm=disposable-template --service qubes.StartApp+xterm

It should instead be:

    $ qvm-run --dispvm=<DISPOSABLE_TEMPLATE> --service qubes.StartApp+xterm

Note that we syntactically distinguish variables in three ways:

1. Surrounding them in angled brackets (`< >`)
2. Using underscores (`_`) instead of spaces between words
3. Using all capital letters

We have observed that many novices make the mistake of typing the surrounding
angled brackets (`< >`) on the command line, even after substituting the
desired real value between them. Therefore, in documentation aimed at novices,
we also recommend clarifying that the angled brackets should not be typed. This
can be accomplished in one of several ways:

- Explicitly say something like "without the angled brackets."
- Provide an example command using real values that excludes the angled
  brackets.
- If you know that almost all users will want to use (or should use) a specific
  command containing all real values and no variables, you might consider
  providing exactly that command and forgoing the version with variables.
  Novices may not realize which parts of the command they can substitute with
  different values, but if you've correctly judged that they should use the
  command you've provided as is, then this shouldn't matter.

## Organizational guidelines

### Do not duplicate documentation

Duplicating documentation is almost always a bad idea. There are many reasons
for this. The main one is that almost all documentation has to be updated as
some point. When similar documentation appears in more than one place, it is
very easy for it to get updated in one place but not the others (perhaps
because the person updating it doesn't realize it's in more than once place).
When this happens, the documentation as a whole is now inconsistent, and the
outdated documentation becomes a trap, especially for novice users. Such traps
are often more harmful than if the documentation never existed in the first
place. The solution is to **link** to existing documentation rather than
duplicating it. There are some exceptions to this policy (e.g., information
that is certain not to change for a very long time), but they are rare.

### Core vs. external documentation

Core documentation resides in the [Qubes OS Project's official
repositories](https://github.com/QubesOS/), mainly in
[qubes-doc](https://github.com/QubesOS/qubes-doc). External documentation can
be anywhere else (such as forums, community websites, and blogs), but there is
an especially large collection in the [Qubes
Community](https://github.com/Qubes-Community) project. External documentation
should not be submitted to [qubes-doc](https://github.com/QubesOS/qubes-doc).
If you've written a piece of documentation that is not appropriate for
[qubes-doc](https://github.com/QubesOS/qubes-doc), we encourage you to submit
it to the [Qubes Community](https://github.com/Qubes-Community) project
instead. However, *linking* to external documentation from
[qubes-doc](https://github.com/QubesOS/qubes-doc) is perfectly fine. Indeed,
the maintainers of the [Qubes Community](https://github.com/Qubes-Community)
project should regularly submit PRs against the documentation index (see [How
to edit the documentation
index](/doc/how-to-edit-the-documentation/#how-to-edit-the-documentation-index))
to add and update Qubes Community links in the ["External
documentation"](/doc/#external-documentation) section of the documentation
table of contents.

The main difference between **core** (or **official**) and **external** (or
**community** or **unofficial**) documentation is whether it documents software
that is officially written and maintained by the Qubes OS Project. The purpose
of this distinction is to keep the core docs maintainable and high-quality by
limiting them to the software output by the Qubes OS Project. In other words,
we take responsibility for documenting all of the software we put out into the
world, but it doesn't make sense for us to take on the responsibility of
documenting or maintaining documentation for anything else. For example, Qubes
OS may use a popular Linux distribution for an official
[TemplateVM](/doc/templates/). However, it would not make sense for a
comparatively small project like ours, with modest funding and a lean
workforce, to attempt to document software belonging to a large, richly-funded
project with an army of paid and volunteer contributors, especially when they
probably already have documentation of their own. This is particularly true
when it comes to Linux in general. Although many users who are new to Qubes are
also new to Linux, it makes absolutely no sense for our comparatively tiny
project to try to document Linux in general when there is already a plethora of
documentation out there.

Many contributors do not realize that there is a significant amount of work
involved in *maintaining* documentation after it has been written. They may
wish to write documentation and submit it to the core docs, but they see only
their own writing process and fail to consider that it will have to be kept
up-to-date and consistent with the rest of the docs for years afterward.
Submissions to the core docs also have to [undergo a review
process](/doc/how-to-edit-the-documentation#security) to ensure accuracy before
being merged, which takes up valuable time from the team. We aim to maintain
high quality standards for the core docs (style and mechanics, formatting),
which also takes up a lot of time. If the documentation involves anything
external to the Qubes OS Project (such as a website, platform, program,
protocol, framework, practice, or even a reference to a version number), the
documentation is likely to become outdated when that external thing changes.
It's also important to periodically review and update this documentation,
especially when a new Qubes release comes out. Periodically, there may be
technical or policy changes that affect all the core documentation. The more
documentation there is relative to maintainers, the harder all of this will be.
Since there are many more people who are willing to write documentation than to
maintain it, these individually small incremental additions amount to a
significant maintenance burden for the project.

On the positive side, we consider the existence of community documentation to
be a sign of a healthy ecosystem, and this is quite common in the software
world. The community is better positioned to write and maintain documentation
that applies, combines, and simplifies the official documentation, e.g.,
tutorials that explain how to install and use various programs in Qubes, how to
create custom VM setups, and introductory tutorials that teach basic Linux
concepts and commands in the context of Qubes. In addition, just because the
Qubes OS Project has officially written and maintains some flexible framework,
such as `qrexec`, it does not make sense to include every tutorial that says
"here's how to do something cool with `qrexec`" in the core docs. Such
tutorials generally also belong in the community documentation.

See [#4693](https://github.com/QubesOS/qubes-issues/issues/4693) for more
background information.

### Release-specific documentation

*See [#5308](https://github.com/QubesOS/qubes-issues/issues/5308) for pending
changes to this policy.*

We maintain only one set of documentation for Qubes OS. We do not maintain a
different set of documentation for each release of Qubes. Our single set of
Qubes OS documentation is updated on a continual, rolling basis. Our first
priority is to document all **current, stable releases** of Qubes. Our second
priority is to document the next, upcoming release (if any) that is currently
in the beta or release candidate stage.

In cases where a documentation page covers functionality that differs
considerably between Qubes OS releases, the page should be subdivided into
clearly-labeled sections that cover the different functionality in different
releases (examples below).

In general, avoid mentioning specific Qubes versions in the body text of
documentation, as these references rapidly go out of date and become misleading
to readers.

#### Incorrect Example

```
## How to Foo

Fooing is the process by which one foos. There are both general and specific
versions of fooing, which vary in usefulness depending on your goals, but for
the most part, all fooing is fooing.

To foo in Qubes 3.2:

   $ qvm-foo <foo-bar>

Note that this does not work in Qubes 4.0, where there is a special widget
for fooing, which you can find in the lower-right corner of the screen in
the Foo Manager. Alternatively, you can use the more general `qubes-baz`
command introduced in 4.0:

   $ qubes-baz --foo <bar>

Once you foo, make sure to close the baz before fooing the next bar.
```

#### Correct Example

```
## Qubes 3.2

### How to Foo

Fooing is the process by which one foos. There are both general and specific
versions of fooing, which vary in usefulness depending on your goals, but for
the most part, all fooing is fooing.

To foo:

   $ qvm-foo <foo-bar>

Once you foo, make sure to close the baz before fooing the next bar.

## Qubes 4.0

### How to Foo

Fooing is the process by which one foos. There are both general and specific
versions of fooing, which vary in usefulness depending on your goals, but for
the most part, all fooing is fooing.

There is a special widget for fooing, which you can find in the lower-right
corner of the screen in the Foo Manager. Alternatively, you can use the
general `qubes-baz` command:

   $ qubes-baz --foo <bar>

Once you foo, make sure to close the baz before fooing the next bar.
```

Subdividing the page into clearly-labeled sections for each release has several
benefits:

- It preserves good content for older (but still supported) releases. Many
  documentation contributors are also people who prefer to use the latest
  release. Many of them are tempted to *replace* existing content that applies
  to an older, supported release with content that applies only to the latest
  release. This is somewhat understandable. Since they only use the latest
  release, they may be focused on their own experience, and they may even
  regard the older release as deprecated, even when it's actually still
  supported. However, allowing this replacement of content would do a great
  disservice to those who still rely on the older, supported release. In many
  cases, these users value the stability and reliability of the older,
  supported release. With the older, supported release, there has been more
  time to fix bugs and make improvements in both the software and the
  documentation. Consequently, much of the documentation content for this
  release may have gone through several rounds of editing, review, and
  revision. It would be a tragedy for this content to vanish while the very set
  of users who most prize stability and reliability are depending on it.
- It's easy for readers to quickly find the information they're looking for,
  since they can go directly to the section that applies to their release.
- It's hard for readers to miss information they need, since it's all in one
  place. In the incorrect example, information that the reader needs could be
  in any paragraph in the entire document, and there's no way to tell without
  reading the entire page. In the correct example, the reader can simply skim
  the headings in order to know which parts of the page need to be read and
  which can be safely ignored. The fact that some content is repeated in the
  two release-specific sections is not a problem, since no reader has to read
  the same thing twice. Moreover, as one release gets updated, it's likely that
  the documentation for that release will also be updated. Therefore, content
  that is initially duplicated between release-specific sections will not
  necessarily stay that way, and this is a good thing: We want the
  documentation for a release that *doesn't* change to stay the same, and we
  want the documentation for a release that *does* change to change along with
  the software.
- It's easy for documentation contributors and maintainers to know which file
  to edit and update, since there's only one page for all Qubes OS releases.
  Initially creating the new headings and duplicating content that applies to
  both is only a one-time cost for each page, and many pages don't even require
  this treatment, since they apply to all currently-supported Qubes OS
  releases.

By contrast, an alternative approach, such as segregating the documentation
into two different branches, would mean that contributions that apply to both
Qubes releases would only end up in one branch, unless someone remembered to
manually submit the same thing to the other branch and actually made the effort
to do so. Most of the time, this wouldn't happen. When it did, it would mean a
second pull request that would have to be reviewed. Over time, the different
branches would diverge in non-release-specific content. Good general content
that was submitted only to one branch would effectively disappear once that
release was deprecated. (Even if it were still on the website, no one would
look at it, since it would explicitly be in the subdirectory of a deprecated
release, and there would be a motivation to remove it from the website so that
search results wouldn't be populated with out-of-date information.)

For further discussion about release-specific documentation in Qubes, see
[here](https://groups.google.com/d/topic/qubes-users/H9BZX4K9Ptk/discussion).

## Git conventions

Please follow our [Git commit message
guidelines](/doc/coding-style/#commit-message-guidelines).