HTMLUnknownElement
Generated from idl/html-elements.webidl when the site was built at 7aa23e2.
HTMLUnknownElement is an interface in idl/html-elements.webidl, inheriting HTMLElement, exposed in Window. What it does is on MDN; this page says what niso has of it.
Status
Section titled “Status”web-features maps none of its members to a feature, so there is no WPT score for it.