R602 [Flexibility] This specification should support common Presentation Formats, which are in use today in Net-enabled applications. In particular, it should support HTML, XHTML, WML and XML as Presentation Formats. It must not preclude the use of other presentation formats (Eilon: such as Flash, GIFs, etc.). Debate on last sentence: AK, CW. I think only XML and HTML (due to its ubiquity) markups should be supported by name, other formats should be considered opaque in the markup stream. Last sentence should read: It must not preclude the use of other presentation formats, although these (e.g., Flash, GIFs, etc.) shall be considered opaque in the markup stream.