[1]
[DFN@en[<[CODE(URI)[[[http://www.w3.org/1999/xhtml]]>]]
は、[[XHTML 1]]および[[HTML 5]]の[[名前空間URI]]です。

[2]
= [[XHTML 1.0]] <IW:XHTML10:"">
= [[XHTML m12n]] <IW:XHTML1m12n:"">
= [[Ruby]]
= [[Web Forms 2.0]]
= [[Web Applications 1.0]]