# valid-lang Enforce the `lang` attribute on the `html` element. The `lang` attribute will only be populated with a value that's [BCP 47](https://www.ietf.org/rfc/bcp/bcp47.txt) compliant ## Rule Details This rule aims to ensure HTML content is [WCAG 3.1.1 compliant](https://www.w3.org/TR/UNDERSTANDING-WCAG20/meaning-doc-lang-id.html). Examples of **incorrect** code for this rule: ```js html` `; ``` ```js html` `; ``` Examples of **correct** code for this rule: ```js html` `; ``` ## Further Reading [MDN: lang](https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/lang)