RE: Namespace name: better to use URN or URL?

[Jeff Lowery <jlowery@scenicsoft.com>]

> Perhaps one thing to clarify is to ask what namespaces are primarily
> intended to do.  If they are meant to uniquely identify 
> something, then use
> URNs.  If they are primarily meant to locate something then, 
> consider URLs.
> If they are primarily meant to do both, then, IMHO, use URNs.

Perhaps unfortunately, namespace are not guaranteed to resolve to anything;
they're just a label. Even if you construct them so that they do resolve,
problems can occur. For example, XML Schema processors don't have to use the
URL or even a schemaLocation attribute to resolve the location of a schema
document. 

Best to consider namespaces as labels, nothing more.