<embed> elements must contain
<noembed> elements. This will provide a description of the content of the
<embed> element in case it does not load.
The engine scans the page for
<embed> elements with missing child or sibling
Users who use assistive tools, such as screen readers, rely on the
<noembed> element to provide a description of the content of the
<embed type="video/webm" src="video.mp4"> <noembed> <h1>Alternative Content</h1> </noembed> </embed>