Use when reviewing or implementing frontend markup structure: clickable divs that should be buttons, links used as buttons, heading/landmark hierarchy, form label/control association, table/list semantics, invalid interactive nesting, overused ARIA replacing native HTML, or markup that breaks the accessibility tree, role-based tests, or hydration. Native HTML/semantic structure scope; for rendered role/name/state/focus regression tests use a11y-contract-testing, for visual design drift use design-to-code-fidelity.
