It strives for predictability of rendering in a changing web support landscape, but it isn't well supported and also binds EPUB to
the XHTML serialization (together with triggers).
It retains its focus on XML - driven toolkits by requiring
XHTML serialization and adding supplementary XML vocabularies, such as MathML and SVG.
Not exact matches
EPUB 3's base content format is now based on the XML
serialization of HTML5 (
XHTML5)[ContentDocs30], whereas EPUB2 supported two basic content types: a profile of
XHTML 1.1 and DTBook [OPS2](a semantically - enhanced markup focused on accessibility concerns).
Currently, the HTML 5 specification refers to this
serialization as «
XHTML 5» [HTML 5, section 1.6]