iframe element Defines an inline frame (ie a frame embedded in a document), samp element Specifies that the enclosed text is sample text and should be rendered in the browser appropriately, command element The command element represents a command which the user can invoke. 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':