Bad links a:not([href]) · a[href=""] · a[href$="#"] · a[href^="javascript:"] · a[disabled]
link without href · empty href · fragment only · javascript href · disabled anchor
Unassociated label label:not(:has(input,textarea,select)):not([for])
Orphan input (warning) input:not(form input)
Figure problems unlabeled · stray figcaption · empty figcaption · aria-label override
No figcaption, no aria-label
Breadcrumbs outside a labeled nav ol[class*="breadcrumb"]:not(nav[aria-label] ol)
Divitis (warning) :is(div > div > div > div > *)
Five levels of divs deep
Nested header nav (warning) header nav:has(ul > ul)
Missing img alt img:not([alt])
Button problems (warnings) button:not([type]) · button:empty