The term "HTML elements"

In section 1.4 (Terminology) it's still not 100% clear to me whether "HTML 
elements" such as those that would be returned by 
HTMLCollection.namedItem(key), would include elements with names not found in 
certain unmentioned specifications such as HTML 4.01.

I mean, it's insufficient to just say "UAs conforming to this specification 
will place elements in HTML" -- which elements are those? -- "in the 
http://www.w3.org/1999/xhtml namespace".

Which elements, if any, would not be in that namespace? I encounter HTML 
documents all the time with custom elements in them; would such elements be 
required to be in that namespace? As a facetious example, 
<DIV><MARQUEE>hello</MARQUEE></DIV> ... would both the DIV and the MARQUEE be
in the XHTML namespace?

What if there are explicit namespace declarations?
What if there's an XML DTD overriding the namespaces?
Does the parser type (HTML, XML) make a diference?

Received on Sunday, 17 June 2007 19:15:25 UTC