RDF In XSD [was: Re: HM.Requirement: authority]

["Sean B. Palmer" <sean@mysterylights.com>]

> RDF is used to annotate XML documents, but has it also
> been used for annotating XML Schemas themselves?

Not regularly, because there is no generally agreed upon mechanism for
doing so. Note that no one is actually looking at the problem, although
some groups are chartered to do so.

XSD does of course have the xsd:annotation and xsd:documentation elements
that can be used to add machine readable descriptions of elements,
complexTypes, and many other XSD constructs. The main problem in figuring
out how RDF can be used to annotate XML schemata is how QNames can be
represented in the RDF model. There have been numerous long-winded and
highly controversial debates on the subject in RDF IG, and some people are
probably getting quite fed up with them by now :-) It's not impossible to
do, there's just very little agreement upon *how* it should be done.

One lingering problem is that the XML namespace specification in and of
itself does not specify an internal structure for QNames; the way in which
they are used is not controlled or constrained, and there is only a
non-normative appendix of the specification that devotes any attention to
it at all. It is a good practice of all XML applications that utilise XML
namespaces that they properly declare the internal structure of their
namespaces, and how the QNames of the application are to be used.

Cheers,

--
Kindest Regards,
Sean B. Palmer
@prefix : <http://webns.net/roughterms/> .
:Sean :hasHomepage <http://purl.org/net/sbp/> .