gitlab-org--gitlab-foss/doc/development/doc_styleguide.md

description
Writing styles, markup, formatting, and reusing regular expressions throughout the GitLab Documentation.

Documentation style guidelines

The documentation style guide defines the markup structure used in GitLab documentation. Check the documentation guidelines for general development instructions.

Check the GitLab handbook for the writing styles guidelines.

Text

• Split up long lines (wrap text), this makes it much easier to review and edit. Only double line breaks are shown as a full line break in GitLab markdown. 80-100 characters is a good line length
• Make sure that the documentation is added in the correct directory and that there's a link to it somewhere useful
• Do not duplicate information
• Be brief and clear
• Unless there's a logical reason not to, add documents in alphabetical order
• Write in US English
• Use single spaces instead of double spaces
• Jump a line between different markups (e.g., after every paragraph, header, list, etc)
• Capitalize "G" and "L" in GitLab
• Use sentence case for titles, headings, labels, menu items, and buttons.
• Use title case when referring to features or products, and methods. Note that some features are also objects (e.g. "Merge Requests" and "merge requests"). E.g.: GitLab Runner, Geo, Issue Boards, Git, Prometheus, Continuous Integration.

Formatting

• Use double asterisks (**) to mark a word or text in bold (**bold**)

• Use undescore (_) for text in italics (_italic_)

• Jump a line between different markups, for example:

  ## Header
  
  Paragraph.
  
  - List item
  - List item
  

Punctuation

For punctuation rules, please refer to the GitLab UX guide.

Ordered and unordered lists

• Use dashes (-) for unordered lists instead of asterisks (*)
• Use the number one (1) for ordered lists
• For punctuation in bullet lists, please refer to the GitLab UX guide

Headings

• Add only one H1 in each document, by adding # at the beginning of it (when using markdown). The h1 will be the document <title>.
• For subheadings, use ##, ### and so on
• Avoid putting numbers in headings. Numbers shift, hence documentation anchor links shift too, which eventually leads to dead links. If you think it is compelling to add numbers in headings, make sure to at least discuss it with someone in the Merge Request
• Avoid using symbols and special chars in headers. Whenever possible, they should be plain and short text.
• Avoid adding things that show ephemeral statuses. For example, if a feature is considered beta or experimental, put this info in a note, not in the heading.
• When introducing a new document, be careful for the headings to be grammatically and syntactically correct. Mention one or all of the following GitLab members for a review: @axil or @marcia. This is to ensure that no document with wrong heading is going live without an audit, thus preventing dead links and redirection issues when corrected
• Leave exactly one newline after a heading

Links

• Use the regular inline link markdown markup [Text](https://example.com). It's easier to read, review, and maintain.
• If there's a link that repeats several times through the same document, you can use [Text][identifier] and at the bottom of the section or the document add: [identifier]: https://example.com, in which case, we do encourage you to also add an alternative text: [identifier]: https://example.com "Alternative text" that appears when hovering your mouse on a link.
• To link to internal documentation, use relative links, not full URLs. Use ../ to navigate tp high-level directories, and always add the file name file.md at the end of the link with the .md extension, not .html. Example: instead of [text](../../merge_requests/), use [text](../../merge_requests/index.md) or, [text](../../ci/README.md), or, for anchor links, [text](../../ci/README.md#examples). Using the markdown extension is necessary for the /help section of GitLab.
• To link from CE to EE-only documentation, use the EE-only doc full URL.
• Use meaningful anchor texts. E.g., instead of writing something like Read more about GitLab Issue Boards [here](LINK), write Read more about [GitLab Issue Boards](LINK).

Images

• Place images in a separate directory named img/ in the same directory where the .md document that you're working on is located. Always prepend their names with the name of the document that they will be included in. For example, if there is a document called twitter.md, then a valid image name could be twitter_login_screen.png. [Exception: images for articles should be put in a directory called img underneath /articles/article_title/img/, therefore, there's no need to prepend the document name to their filenames.]
• Images should have a specific, non-generic name that will differentiate them.
• Keep all file names in lower case.
• Consider using PNG images instead of JPEG.
• Compress all images with https://tinypng.com/ or similar tool.
• Compress gifs with https://ezgif.com/optimize or similar tool.
• Images should be used (only when necessary) to illustrate the description of a process, not to replace it.

Inside the document:

• The Markdown way of using an image inside a document is: ![Proper description what the image is about](img/document_image_title.png)
• Always use a proper description for what the image is about. That way, when a browser fails to show the image, this text will be used as an alternative description
• If there are consecutive images with little text between them, always add three dashes (---) between the image and the text to create a horizontal line for better clarity
• If a heading is placed right after an image, always add three dashes (---) between the image and the heading

Alert boxes

Whenever you want to call the attention to a particular sentence, use the following markup for highlighting.

Note that the alert boxes only work for one paragraph only. Multiple paragraphs, lists, headers, etc will not render correctly.

Note

NOTE: **Note:**
This is something to note.

How it renders in docs.gitlab.com:

NOTE: Note: This is something to note.

Tip

TIP: **Tip:**
This is a tip.

How it renders in docs.gitlab.com:

TIP: Tip: This is a tip.

Caution

CAUTION: **Caution:**
This is something to be cautious about.

How it renders in docs.gitlab.com:

CAUTION: Caution: This is something to be cautious about.

Danger

DANGER: **Danger:**
This is a breaking change, a bug, or something very important to note.

How it renders in docs.gitlab.com:

DANGER: Danger: This is a breaking change, a bug, or something very important to note.

Blockquotes

For highlighting a text within a blue blockquote, use this format:

> This is a blockquote.

which renders in docs.gitlab.com to:

This is a blockquote.

If the text spans across multiple lines it's OK to split the line.

Specific sections and terms

To mention and/or reference specific terms in GitLab, please follow the styles below.

GitLab versions and tiers

• Every piece of documentation that comes with a new feature should declare the GitLab version that feature got introduced. Right below the heading add a note:

  > Introduced in GitLab 8.3.
  

• Whenever possible, every feature should have a link to the MR, issue, or epic that introduced it. The above note would be then transformed to:

  > [Introduced][ce-1242] in GitLab 8.3.
  

  , where the link identifier is named after the repository (CE) and the MR number.

• If the feature is only available in GitLab Enterprise Edition, don't forget to mention the paid tier the feature is available in:

  > [Introduced][ee-1234] in [GitLab Starter](https://about.gitlab.com/pricing/) 8.3.
  

Product badges

When a feature is available in EE-only tiers, add the corresponding tier according to the feature availability:

• For GitLab Starter and GitLab.com Bronze: **[STARTER]**
• For GitLab Premium and GitLab.com Silver: **[PREMIUM]**
• For GitLab Ultimate and GitLab.com Gold: **[ULTIMATE]**
• For GitLab Core and GitLab.com Free: **[CORE]**

To exclude GitLab.com tiers (when the feature is not available in GitLab.com), add the keyword "only":

• For GitLab Starter: **[STARTER ONLY]**
• For GitLab Premium: **[PREMIUM ONLY]**
• For GitLab Ultimate: **[ULTIMATE ONLY]**
• For GitLab Core: **[CORE ONLY]**

The tier should be ideally added to headers, so that the full badge will be displayed. But it can be also mentioned from paragraphs, list items, and table cells. For these cases, the tier mention will be represented by an orange question mark. E.g., **[STARTER]** renders [STARTER], **[STARTER ONLY]** renders [STARTER ONLY].

The absence of tiers' mentions mean that the feature is available in GitLab Core, GitLab.com Free, and higher tiers.

How it works

Introduced by !244, the special markup **[STARTER]** will generate a span element to trigger the badges and tooltips (<span class="badge-trigger starter">). When the keyword "only" is added, the corresponding GitLab.com badge will not be displayed.

GitLab Restart

There are many cases that a restart/reconfigure of GitLab is required. To avoid duplication, link to the special document that can be found in doc/administration/restart_gitlab.md. Usually the text will read like:

Save the file and [reconfigure GitLab](../administration/restart_gitlab.md)
for the changes to take effect.

If the document you are editing resides in a place other than the GitLab CE/EE doc/ directory, instead of the relative link, use the full path: http://docs.gitlab.com/ce/administration/restart_gitlab.html. Replace reconfigure with restart where appropriate.

Installation guide

Ruby: In step 2 of the installation guide, we install Ruby from source. Whenever there is a new version that needs to be updated, remember to change it throughout the codeblock and also replace the sha256sum (it can be found in the downloads page of the Ruby website).

Configuration documentation for source and Omnibus installations

GitLab currently officially supports two installation methods: installations from source and Omnibus packages installations.

Whenever there is a setting that is configurable for both installation methods, prefer to document it in the CE docs to avoid duplication.

Configuration settings include:

• settings that touch configuration files in config/
• NGINX settings and settings in lib/support/ in general

When there is a list of steps to perform, usually that entails editing the configuration file and reconfiguring/restarting GitLab. In such case, follow the style below as a guide:

**For Omnibus installations**

1. Edit `/etc/gitlab/gitlab.rb`:

    ```ruby
    external_url "https://gitlab.example.com"
    ```

1. Save the file and [reconfigure] GitLab for the changes to take effect.

---

**For installations from source**

1. Edit `config/gitlab.yml`:

    ```yaml
    gitlab:
      host: "gitlab.example.com"
    ```

1. Save the file and [restart] GitLab for the changes to take effect.


[reconfigure]: path/to/administration/restart_gitlab.md#omnibus-gitlab-reconfigure
[restart]: path/to/administration/restart_gitlab.md#installations-from-source

In this case:

• before each step list the installation method is declared in bold
• three dashes (---) are used to create a horizontal line and separate the two methods
• the code blocks are indented one or more spaces under the list item to render correctly
• different highlighting languages are used for each config in the code block
• the references guide is used for reconfigure/restart

Fake tokens

There may be times where a token is needed to demonstrate an API call using cURL or a secret variable used in CI. It is strongly advised not to use real tokens in documentation even if the probability of a token being exploited is low.

You can use the following fake tokens as examples.

Token type	Token value
Private user token	9koXpg98eAheJpvBs5tK
Personal access token	n671WNGecHugsdEDPsyo
Application ID	2fcb195768c39e9a94cec2c2e32c59c0aad7a3365c10892e8116b5d83d4096b6
Application secret	04f294d1eaca42b8692017b426d53bbc8fe75f827734f0260710b83a556082df
Secret CI variable	Li8j-mLUVA3eZYjPfd_H
Specific Runner token	yrnZW46BrtBFqM7xDzE7dddd
Shared Runner token	6Vk7ZsosqQyfreAxXTZr
Trigger token	be20d8dcc028677c931e04f3871a9b
Webhook secret token	6XhDroRcYPM5by_h-HLY
Health check token	Tu7BgjR9qeZTEyRzGG2P
Request profile token	7VgpS4Ax5utVD2esNstz

API

Here is a list of must-have items. Use them in the exact order that appears on this document. Further explanation is given below.

• Every method must have the REST API request. For example:

  GET /projects/:id/repository/branches
  

• Every method must have a detailed description of the parameters.

• Every method must have a cURL example.

• Every method must have a response body (in JSON format).

Method description

Use the following table headers to describe the methods. Attributes should always be in code blocks using backticks (`).

| Attribute | Type | Required | Description |
| --------- | ---- | -------- | ----------- |

Rendered example:

Attribute	Type	Required	Description
user	string	yes	The GitLab username

cURL commands

• Use https://gitlab.example.com/api/v4/ as an endpoint.
• Wherever needed use this personal access token: 9koXpg98eAheJpvBs5tK.
• Always put the request first. GET is the default so you don't have to include it.
• Use double quotes to the URL when it includes additional parameters.
• Prefer to use examples using the personal access token and don't pass data of username and password.

Methods	Description
-H "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK"	Use this method as is, whenever authentication needed
-X POST	Use this method when creating new objects
-X PUT	Use this method when updating existing objects
-X DELETE	Use this method when removing existing objects

cURL Examples

Below is a set of cURL examples that you can use in the API documentation.

Simple cURL command

Get the details of a group:

curl --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" https://gitlab.example.com/api/v4/groups/gitlab-org

cURL example with parameters passed in the URL

Create a new project under the authenticated user's namespace:

curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects?name=foo"

Post data using cURL's --data

Instead of using -X POST and appending the parameters to the URI, you can use cURL's --data option. The example below will create a new project foo under the authenticated user's namespace.

curl --data "name=foo" --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects"

Post data using JSON content

Note: In this example we create a new group. Watch carefully the single and double quotes.

curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" --header "Content-Type: application/json" --data '{"path": "my-group", "name": "My group"}' https://gitlab.example.com/api/v4/groups

Post data using form-data

Instead of using JSON or urlencode you can use multipart/form-data which properly handles data encoding:

curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" --form "title=ssh-key" --form "key=ssh-rsa AAAAB3NzaC1yc2EA..." https://gitlab.example.com/api/v4/users/25/keys

The above example is run by and administrator and will add an SSH public key titled ssh-key to user's account which has an id of 25.

Escape special characters

Spaces or slashes (/) may sometimes result to errors, thus it is recommended to escape them when possible. In the example below we create a new issue which contains spaces in its title. Observe how spaces are escaped using the %20 ASCII code.

curl --request POST --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" "https://gitlab.example.com/api/v4/projects/42/issues?title=Hello%20Dude"

Use %2F for slashes (/).

Pass arrays to API calls

The GitLab API sometimes accepts arrays of strings or integers. For example, to restrict the sign-up e-mail domains of a GitLab instance to *.example.com and example.net, you would do something like this:

curl --request PUT --header "PRIVATE-TOKEN: 9koXpg98eAheJpvBs5tK" --data "domain_whitelist[]=*.example.com" --data "domain_whitelist[]=example.net" https://gitlab.example.com/api/v4/application/settings