Acceptance Criteria

• The listed features are documented sufficiently on MDN
  The :has() page exists. The description and examples need to be improved.
  This work will be tracked separately here: Improve the :has() page documentation #19972
• BCD is updated
  FF103 CSS :has() selector browser-compat-data#17353
• Interactive example and data repos are updated if appropriate
• The content has been reviewed as needed

For folks helping with Firefox related documentation

• Set bugs to dev-doc-complete
• Add entry to Firefox release notes if feature is enabled in release - NA
  or
• Add entry to Firefox experimental features page if feature is not yet enabled in release
  Adds :has() to experimental feature list #19970

Features to document

Related Gecko bugs

https://bugzilla.mozilla.org/show_bug.cgi?id=1771896

Other