> For the complete documentation index, see [llms.txt](https://docs.vale.sh/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.vale.sh/formats/myst.md).

# MyST

Learn how Vale handles MyST content.

{% hint style="info" %}
Requires Vale v3.18.0 or later.
{% endhint %}

[MyST](https://myst-parser.readthedocs.io/) is CommonMark plus Sphinx-style constructs—directives, roles, targets, comments, and block breaks—that a plain Markdown parser reads as prose. Vale parses each one as the markup it is.

The supported extension is `.myst`. A Markdown file opts in through a [format association](/topics/.vale.ini.md#format-associations):

```ini
[formats]
md = myst

[*.{md,myst}]
BasedOnStyles = Vale
```

By default, Vale ignores:

* Targets: `(my-label)=` lines.
* Roles: the `{name}` of `` {term}`content` ``—the span that follows is a code span, ignored like any other.
* Comments: lines beginning with `%`.
* Block breaks: `+++` lines, including any metadata they carry.
* Directive options: `:key: value` lines and `---`-delimited YAML blocks under a directive opener.
* Substitutions: `{{ variable }}`.
* Attributes: `{.class}` lines and the `{.class}` of `[text]{.class}`—the text itself is still linted.
* Fenced blocks, code spans, and URLs, as in [Markdown](/formats/markdown.md).

## [Directives](#directives)

A directive's content is Markdown, and Vale lints it—whether the directive is fenced with backticks or colons:

```
:::{note}
This prose is linted.
:::
```

The exception is a directive whose content is literal rather than prose: `code`, `code-block`, `code-cell`, `csv-table`, `eval-rst`, `highlight`, `include`, `literalinclude`, `math`, `mermaid`, `raw`, `sourcecode`, and `toctree` are ignored in full.

A directive's name also becomes a [class scope](/topics/scopes.md#class-scopes) for everything inside it, however deeply nested:

```yaml
extends: existence
message: "Don't use '%s' in an admonition."
scope: class.note
level: error
tokens:
  - obviously
```

## [Math and citations](#math-and-citations)

Math is ignored, both `$$…$$` display blocks and `$x^2$` inline spans. See [Math](/formats/markdown.md#math) for the delimiter rules, which are what keep `It costs $5 and $10` prose.

Citations (`[@ref]`) are read as prose, since a bare bracket is ordinary punctuation more often than not. To exclude them, use [`TokenIgnores`](/keys/tokenignores.md):

```ini
[*.{md,myst}]
TokenIgnores = (\[@[^\n\]]+\])
```


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.vale.sh/formats/myst.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.