audio element The audio element is used to embed sound content in an HTML or XHTML document, keygen element The HTML keygen element exists to facilitate generation of key material, and submission of the public key as part of an HTML form, strong element Specifies that the enclosed text should be rendered in the browser as "strong" (usually bold) text. These elements allows child elements from interactive, embedded, heading, sectioning, phrasing, and metadata content categories.
Click the html element name in the punctuation list to advance the example in 'Tryit-Editor':