This rule template can be used to create rules which will be triggered when an @-rule matches a given regular expression.

For example, one can create a rule with the regular expression `(charset|font-face)` to match `charset` and `font-face` @-rules (to warn developers not to use them for some reasons for instance).

Note that, in order to match `charset` and `font-face` @-rules regardless of the case, the `(?i)` modifier can be prepended to the expression, as in `(?i)(charset|font-face)`.

See Java documentation for detailed regular expression syntax.

## stylelint Related Rules

- at-rule-blacklist
- at-rule-whitelist