# `Ignore`: Skip-formatting ("ignore") comments -- the mdformat #53 gap, filled for MyST

```{py:currentmodule} myform.Ignore
```

mdformat core has no way to exempt content from formatting. This module adds the family every
other formatter ships, as configurable HTML comments (already valid CommonMark, so no new grammar):

- `<!-- myform-ignore -->` preserves the *next* block verbatim;
- `<!-- myform-ignore-start -->` ... `<!-- myform-ignore-end -->` a range;
- `<!-- myform-ignore-file -->` the whole file.

Markers act only at the **document top level**: one nested inside a list item or blockquote is left
as an ordinary comment and does not suppress formatting -- acting on it would unbalance the spliced
token tree and re-apply the container's prefix to the preserved source every run. The marker strings
are configurable via `MystOptions`.

The mechanism is a `markdown-it` core rule that runs after block parsing: the tokens of an ignored
span are replaced by a single `myst_ignored` token carrying the span's *original source*, which
`Renderer.render_myst_ignored` emits verbatim (an `html_block` carrier would `lstrip` the first
line and de-indent preserved code). The replacement is ephemeral -- internal to one render -- and
the emitted markdown is re-parsed fresh on the next run, so formatting stays idempotent (the marker
comments are themselves preserved and re-detected).

```{eval-rst}
.. automodule:: myform.Ignore
   :members:
```