XHTML1: Appendix C.13 seems misplaced/flawed

Dear HTML Working Group,

  Appendix C.13 of the XHTML 1.0 Second Edition Recommendation states:

[...]
  3. Within the XHTML namespace, user agents are expected to recognize
     the "id" attribute as an attribute of type ID. Therefore, style
     sheets should be able to continue using the shorthand "#" selector
     syntax even if the user agent does not read the DTD. 

  4. Within the XHTML namespace, user agents are expected to recognize
     the "class" attribute. Therefore, style sheets should be able to
     continue using the shorthand "." selector syntax. 
[...]

It is not clear to me what you mean by "Within the XHTML namespace". Do
you mean on elements in the XHTML namespace as defined in section 3.1.1
or do you mean attributes in the XHTML namesapce as defined in section
3.1.1 on arbitrary elements?

It is also not clear to me why user agents are expected to do as the
section suggests, section 3.2 does not cite such a requirement. Do you
mean that e.g. if an XHTML 1.0 user agent encounters an XHTML 1.1
document that uses ruby elements, it must not only process the content
of the unrecognized attributes, but also process id, class, xml:lang
attributes? That would seem inconsistent with section 3.2 which clearly
states

[...]
  When a user agent processes an XHTML document as generic XML, it shall
  only recognize attributes of type ID (i.e. the id attribute on most
  XHTML elements) as fragment identifiers. 
[...]

as it does not know whether such attributes are ID attributes unless it
processes the document type definition which it is not required to do,
as far as I understand. But then, this part of section 3.2 does not make
much sense to me. I cannot think of a situation where an XHTML user
agent would process an XHTML document as "generic XML" and still be
considered an XHTML user agent. It seems that XHTML user agents would
always process XHTML documents as XHTML documents or they are not XHTML
user agents. But then, maybe my confusion is caused by the lack of
definition for "generic XML".

In either case, if there is such an expectation, you need to clearly
state this somewhere, not in the informative Appendix C.

That said, it seems that the entire Appendix C.13 seems misplaced in
Appendix C as it does not seem to contain guidelines for XHTML authors
who wish to deliver their documents to legacy user agents. Could you
please clarify what requirements they have to meet in order to do so?
If there is no requirement, the appropriate section for the section
seems to be section 4, "Differences with HTML 4".

regards.

Received on Monday, 12 July 2004 00:14:50 UTC