Re: Using RELAX NG in XHTML 2.0

Masayasu Ishikawa <> wrote in

> Having said that, the WG would try to approximate intended
> constraints to the extent possible by DTD if people still find
> it useful, but I'm still not convinced that requiring DTD
> validity is a good idea.

I agree. Requiring DTD validity to be a conforming XHTML document
means that we can have two canonically equivalent XHTML documents,
where one is valid (and conforming), and the other is not.


Document 1:
<html xmlns=""

Document 2:
<prefix:html xmlns:prefix=""

These are equivalent, but only the first would be valid XHTML 1.0.
And yes, this could be a problem in practice. For example, an XSLT
transformation on two identical source documents could lead to
either of these resulting documents.

Karl Ove Hufthammer

Received on Wednesday, 14 May 2003 17:47:03 UTC