gitlab-org--gitlab-foss/doc/markdown/markdown.md

Markdown

Table of Contents

GitLab Flavored Markdown

• Newlines
• Multiple underscores in words
• URL auto-linking
• Code and Syntax Highlighting
• Emoji
• Special GitLab references
• Task lists

Standard Markdown

• Headers
• Emphasis
• Lists
• Links
• Images
• Blockquotes
• Inline HTML
• Horizontal Rule
• Line Breaks
• Tables

References

GitLab Flavored Markdown (GFM)

GitLab uses the Redcarpet Ruby library for Markdown processing.

For GitLab we developed something we call "GitLab Flavored Markdown" (GFM). It extends the standard Markdown in a few significant ways to add some useful functionality.

You can use GFM in

• comments
• issues
• merge requests
• milestones
• wiki pages

You can also use other rich text files in GitLab. You might have to install a dependency to do so. Please see the github-markup gem readme for more information.

Newlines

GFM honors the markdown specification in how paragraphs and line breaks are handled.

A paragraph is simply one or more consecutive lines of text, separated by one or more blank lines.
Line-breaks, or softreturns, are rendered if you end a line with two or more spaces

Roses are red [followed by two or more spaces]  
Violets are blue

Sugar is sweet

Roses are red
Violets are blue

Sugar is sweet

Multiple underscores in words

It is not reasonable to italicize just part of a word, especially when you're dealing with code and names that often appear with multiple underscores. Therefore, GFM ignores multiple underscores in words.

perform_complicated_task
do_this_and_do_that_and_another_thing

perform_complicated_task
do_this_and_do_that_and_another_thing

URL auto-linking

GFM will autolink almost any URL you copy and paste into your text.

* https://www.google.com
* https://google.com/
* ftp://ftp.us.debian.org/debian/
* smb://foo/bar/baz
* irc://irc.freenode.net/gitlab
* http://localhost:3000

• https://www.google.com
• https://google.com/
• ftp://ftp.us.debian.org/debian/
• smb://foo/bar/baz
• irc://irc.freenode.net/gitlab
• http://localhost:3000

Code and Syntax Highlighting

GitLab uses the Rouge Ruby library for syntax highlighting. For a list of supported languages visit the Rouge website.

Blocks of code are either fenced by lines with three back-ticks ```, or are indented with four spaces. Only the fenced code blocks support syntax highlighting.

Inline `code` has `back-ticks around` it.

Inline code has back-ticks around it.

Example:

```javascript
var s = "JavaScript syntax highlighting";
alert(s);
```

```python
def function():
    #indenting works just fine in the fenced code block
    s = "Python syntax highlighting"
    print s
```

```ruby
require 'redcarpet'
markdown = Redcarpet.new("Hello World!")
puts markdown.to_html
```

```
No language indicated, so no syntax highlighting.
s = "There is no highlighting for this."
But let's throw in a <b>tag</b>.
```

becomes:

var s = "JavaScript syntax highlighting";
alert(s);

def function():
    #indenting works just fine in the fenced code block
    s = "Python syntax highlighting"
    print s

require 'redcarpet'
markdown = Redcarpet.new("Hello World!")
puts markdown.to_html

No language indicated, so no syntax highlighting.
s = "There is no highlighting for this."
But let's throw in a <b>tag</b>.

Emoji

Sometimes you want to :monkey: around a bit and add some :star2: to your :speech_balloon:. Well we have a gift for you:

:zap: You can use emoji anywhere GFM is supported. :v:

You can use it to point out a :bug: or warn about :speak_no_evil: patches. And if someone improves your really :snail: code, send them some :birthday:. People will :heart: you for that.

If you are new to this, don't be :fearful:. You can easily join the emoji :family:. All you need to do is to look up on the supported codes.

Consult the [Emoji Cheat Sheet](http://emoji.codes) for a list of all supported emoji codes. :thumbsup:

Sometimes you want to 🐒 around a bit and add some 🌟 to your 💬. Well we have a gift for you:

⚡ You can use emoji anywhere GFM is supported. ✌️

You can use it to point out a 🐛 or warn about 🙊 patches. And if someone improves your really 🐌 code, send them some 🎂. People will ❤️ you for that.

If you are new to this, don't be 😨. You can easily join the emoji 👪. All you need to do is to look up on the supported codes.

Consult the Emoji Cheat Sheet for a list of all supported emoji codes. 👍

Special GitLab References

GFM recognizes special references.

You can easily reference e.g. an issue, a commit, a team member or even the whole team within a project.

GFM will turn that reference into a link so you can navigate between them easily.

GFM will recognize the following:

input	references
@user_name	specific user
@group_name	specific group
@all	entire team
#123	issue
!123	merge request
$123	snippet
~123	label by ID
~bug	one-word label by name
~"feature request"	multi-word label by name
9ba12248	specific commit
9ba12248...b19a04f5	commit range comparison
[README](doc/README)	repository file references

GFM also recognizes certain cross-project references:

input	references
namespace/project#123	issue
namespace/project!123	merge request
namespace/project$123	snippet
namespace/project@9ba12248	specific commit
namespace/project@9ba12248...b19a04f5	commit range comparison
namespace/project~"Some label"	issues with given label

Task Lists

You can add task lists to issues, merge requests and comments. To create a task list, add a specially-formatted Markdown list, like so:

- [x] Completed task
- [ ] Incomplete task
    - [ ] Sub-task 1
    - [x] Sub-task 2
    - [ ] Sub-task 3

• Completed task
• Incomplete task
  • Sub-task 1
  • Sub-task 2
  • Sub-task 3

Task lists can only be created in descriptions, not in titles. Task item state can be managed by editing the description's Markdown or by toggling the rendered check boxes.

Standard Markdown

Headers

# H1
## H2
### H3
#### H4
##### H5
###### H6

Alternatively, for H1 and H2, an underline-ish style:

Alt-H1
======

Alt-H2
------

H1

H2

H3

H4

H5

H6

Alternatively, for H1 and H2, an underline-ish style:

Alt-H1

Alt-H2

Header IDs and links

All Markdown-rendered headers automatically get IDs, except in comments.

On hover a link to those IDs becomes visible to make it easier to copy the link to the header to give it to someone else.

The IDs are generated from the content of the header according to the following rules:

1. All text is converted to lowercase
2. All non-word text (e.g., punctuation, HTML) is removed
3. All spaces are converted to hyphens
4. Two or more hyphens in a row are converted to one
5. If a header with the same ID has already been generated, a unique incrementing number is appended, starting at 1.

For example:

# This header has spaces in it
## This header has a :thumbsup: in it
# This header has Unicode in it: 한글
## This header has spaces in it
### This header has spaces in it

Would generate the following link IDs:

1. this-header-has-spaces-in-it
2. this-header-has-a-in-it
3. this-header-has-unicode-in-it-한글
4. this-header-has-spaces-in-it
5. this-header-has-spaces-in-it-1

Note that the Emoji processing happens before the header IDs are generated, so the Emoji is converted to an image which then gets removed from the ID.

Emphasis

Emphasis, aka italics, with *asterisks* or _underscores_.

Strong emphasis, aka bold, with **asterisks** or __underscores__.

Combined emphasis with **asterisks and _underscores_**.

Strikethrough uses two tildes. ~~Scratch this.~~

Emphasis, aka italics, with asterisks or underscores.

Strong emphasis, aka bold, with asterisks or underscores.

Combined emphasis with asterisks and underscores.

Strikethrough uses two tildes. Scratch this.

Lists

1. First ordered list item
2. Another item
  * Unordered sub-list.
1. Actual numbers don't matter, just that it's a number
  1. Ordered sub-list
4. And another item.

* Unordered list can use asterisks
- Or minuses
+ Or pluses

1. First ordered list item
2. Another item

• Unordered sub-list.

1. Actual numbers don't matter, just that it's a number
2. Ordered sub-list
3. And another item.

• Unordered list can use asterisks

• Or minuses

• Or pluses

If a list item contains multiple paragraphs, each subsequent paragraph should be indented with four spaces.

1.  First ordered list item

    Second paragraph of first item.
2.  Another item

1. First ordered list item

   Second paragraph of first item.

2. Another item

If the second paragraph isn't indented with four spaces, the second list item will be incorrectly labeled as 1.

1. First ordered list item

   Second paragraph of first item.
2. Another item

1. First ordered list item

   Second paragraph of first item.

2. Another item

Links

There are two ways to create links, inline-style and reference-style.

[I'm an inline-style link](https://www.google.com)

[I'm a reference-style link][Arbitrary case-insensitive reference text]

[I'm a relative reference to a repository file](LICENSE)

[You can use numbers for reference-style link definitions][1]

Or leave it empty and use the [link text itself][]

Some text to show that the reference links can follow later.

[arbitrary case-insensitive reference text]: https://www.mozilla.org
[1]: http://slashdot.org
[link text itself]: https://www.reddit.com

I'm an inline-style link

I'm a reference-style link

I'm a relative reference to a repository file

You can use numbers for reference-style link definitions

Or leave it empty and use the link text itself

Some text to show that the reference links can follow later.

Note

Relative links do not allow referencing project files in a wiki page or wiki page in a project file. The reason for this is that, in GitLab, wiki is always a separate git repository. For example:

[I'm a reference-style link](style)

will point the link to wikis/style when the link is inside of a wiki markdown file.

Images

Here's our logo (hover to see the title text):

Inline-style:
![alt text](img/logo.png)

Reference-style:
![alt text1][logo]

[logo]: img/logo.png

Here's our logo:

Inline-style:

Reference-style:

Blockquotes

> Blockquotes are very handy in email to emulate reply text.
> This line is part of the same quote.

Quote break.

> This is a very long line that will still be quoted properly when it wraps. Oh boy let's keep writing to make sure this is long enough to actually wrap for everyone. Oh, you can *put* **Markdown** into a blockquote.

Blockquotes are very handy in email to emulate reply text. This line is part of the same quote.

Quote break.

This is a very long line that will still be quoted properly when it wraps. Oh boy let's keep writing to make sure this is long enough to actually wrap for everyone. Oh, you can put Markdown into a blockquote.

Inline HTML

You can also use raw HTML in your Markdown, and it'll mostly work pretty well.

See the documentation for HTML::Pipeline's SanitizationFilter class for the list of allowed HTML tags and attributes. In addition to the default SanitizationFilter whitelist, GitLab allows span elements.

<dl>
  <dt>Definition list</dt>
  <dd>Is something people use sometimes.</dd>

  <dt>Markdown in HTML</dt>
  <dd>Does *not* work **very** well. Use HTML <em>tags</em>.</dd>
</dl>

Definition list

Is something people use sometimes.

Markdown in HTML

Does *not* work **very** well. Use HTML tags.

Horizontal Rule

Three or more...

---

Hyphens

***

Asterisks

___

Underscores

Three or more...

---

Hyphens

---

Asterisks

---

Underscores

Line Breaks

My basic recommendation for learning how line breaks work is to experiment and discover -- hit <Enter> once (i.e., insert one newline), then hit it twice (i.e., insert two newlines), see what happens. You'll soon learn to get what you want. "Markdown Toggle" is your friend.

Here are some things to try out:

Here's a line for us to start with.

This line is separated from the one above by two newlines, so it will be a *separate paragraph*.

This line is also a separate paragraph, but...
This line is only separated by a single newline, so it's a separate line in the *same paragraph*.

This line is also a separate paragraph, and...  
This line is on its own line, because the previous line ends with two
spaces.

Here's a line for us to start with.

This line is separated from the one above by two newlines, so it will be a separate paragraph.

This line is also begins a separate paragraph, but... This line is only separated by a single newline, so it's a separate line in the same paragraph.

This line is also a separate paragraph, and...
This line is on its own line, because the previous line ends with two spaces.

Tables

Tables aren't part of the core Markdown spec, but they are part of GFM and Markdown Here supports them.

| header 1 | header 2 |
| -------- | -------- |
| cell 1   | cell 2   |
| cell 3   | cell 4   |

Code above produces next output:

header 1	header 2
cell 1	cell 2
cell 3	cell 4

Note

The row of dashes between the table header and body must have at least three dashes in each column.

By including colons in the header row, you can align the text within that column:

| Left Aligned | Centered | Right Aligned | Left Aligned | Centered | Right Aligned |
| :----------- | :------: | ------------: | :----------- | :------: | ------------: |
| Cell 1       | Cell 2   | Cell 3        | Cell 4       | Cell 5   | Cell 6        |
| Cell 7       | Cell 8   | Cell 9        | Cell 10      | Cell 11  | Cell 12       |

Left Aligned	Centered	Right Aligned	Left Aligned	Centered	Right Aligned
Cell 1	Cell 2	Cell 3	Cell 4	Cell 5	Cell 6
Cell 7	Cell 8	Cell 9	Cell 10	Cell 11	Cell 12

References

• This document leveraged heavily from the Markdown-Cheatsheet.
• The Markdown Syntax Guide at Daring Fireball is an excellent resource for a detailed explanation of standard markdown.
• Dillinger.io is a handy tool for testing standard markdown.