Use of Triples with Newly Created XML Languages

Hi Noah, 
 
I promised to write down the additional comment I had, about [1], at the
end of this week's F2F, as we were running out of time.
 
In section 4.3 and 4.4 are two good practice notes about ways to make HTML
documents and XML documents self describing.
 
I think there is another case not explicitly covered by these and that I
would like to see covered. This is the case where an XML language is
created with explicit mechanisms for relating its constructs to triples.
The example I was thinking of is XHTML 2 [2] and, by extension DIAL, [3].
The XHTML 2 'role' [4] attribute and facilities in the metainformation
module [5] support use of or reference to RDF triples. At a quick glance,
[5] looks similar to RDFa, and may indeed be the source of the concept.
The same people are involved in both.
 
It could be that relaxing the good practice note about RDFa to something
more general about languages that support such constructs could allow the
XHTML 2 case to be included. Also, this seems to be a case where an XML
language would not need to use GRDDL because it has native ways of
achieving the same objective. That might argue for relaxing the good
practice note about XML languages and GRDDL in 4.4. 
 
Does that make sense? 
 
Best wishes
Rhys
 
[1] http://www.w3.org/2001/tag/doc/selfDescribingDocuments-2007-05-24.html
[2] http://www.w3.org/TR/xhtml2/
[3] http://www.w3.org/TR/dial/
[4]
http://www.w3.org/TR/xhtml2/mod-roleAttribute.html#s_roleAttributemodule
[5]
http://www.w3.org/TR/xhtml2/mod-metaAttributes.html#s_metaAttributesmodule