The following markup elements are not supported by default, but can be added using markdown-it plugins.

## Subscript

Plugin: markdown-it-sub

To output a character in subscript, add ~ on both sides.

H~2~O


You can vote to include subscript support in YFM by default in GitHub issues.

## Underlined text

Plugin: markdown-it-ins

To underline text, add ++ on both sides.

++qwerty++


You can vote to include underlined text support in YFM by default in GitHub issues.

## Footnotes

Plugin: markdown-it-footnote

Use footnotes for additional information without complicating the text. Footnotes have two parts connected with tags:

• The link in the document text, which is displayed as superscript.
• A block of additional information. It's usually placed at the end of the document.
Here's a simple footnote,[^1] and here's a longer one.[^bignote]

[^1]: This is the first footnote.

[^bignote]: Here's one with multiple paragraphs and code.


You can vote to include footnote support in YFM by default in GitHub issues.

Import plugin from package like so:

const checkbox = require('@doc-tools/transform/lib/plugins/checkbox');


The task list is a list of checkboxes. A normal item is represented by the - [ ] symbol, a checked one by - [x].

- [x] Write the press release
- [ ] Update the website
- [ ] Contact the media


You can vote to include task list support in YFM by default in GitHub issues.

## Formulas

Plugin: markdown-it-katex (see other versions)

The plugin uses the KaTeX library to display mathematical symbols. Example of a formula:

$\sqrt{3x-1}+(1+x)^2$