iframe element Defines an inline frame (ie a frame embedded in a document), abbr element Specifies that a string is an abbreviation for a longer word or phrase, base element Specifies a base URL for all of the relative URLs in the document to use. 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':