xml-dev - Namespace Basic Principles

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

Simple question:-

<div xmlns="http://www.w3.org/1999/xhtml" />

It has often been siad that the most useful characteristic of having a
unique name for XML is simply that it is therfore unique.
The above example is an XHTML div element. But how do we know it is XHTML?
It has the unique XHTML namespace... but how does that tell us it is
"XHTML"? Because it has "xhtml" in the URI? Because by human dereferencing
it we get a prose definition of XHTML? Because the W3C owns the URI and
they said so?
So tell me, how do we know that the above is an XHTML div element, and does
it actually matter if it is or it isn't? What I mean is "is it alright to
simply have the property of uniqueness in this case?" If so, then what
about:-

<myelement xmlns="http://www.w3.org/1999/xhtml" />

Or even better:-

<myelement xmlns="http://www.w3.org/1999/xhtml">
<div> </div>
</myelement>

Remember that this needs to be a practical debate: how useful would an HTML
processor (read: browser) find it to have an XHTML namespace in all HTML
documents? How about the same question for an XML parser? How about for a
Semantic Web engine?

For the record: I think that an HTML processor could jsut "recognize" the
xmlns. An XML processor would just say "well, it's unique", and an SW
engine would try to dereference it.

Kindest Regards,
Sean B. Palmer
http://infomesh.net/sbp/
http://www.w3.org/WAI/ [ERT/GL/PF]
"Perhaps, but let's not get bogged down in semantics."
   - Homer J. Simpson, BABF07.