RE: Name Space Question

[Mike Brown <mbrown@corp.webb.net>]

> In other words, does namespace uniquely identify the elements
> defined in an XML Schema in relationship to elements in 
> another XML schema or the relationship of elements in a
> document to other documents?

Strictly speaking, namespaces apply to elements only, no matter what context
-- document or schema -- they appear in.

The namespace identifies a class of element types (names), thereby allowing
elements of the same type but that have different semantics to be
disambiguated. The intent, as per the opening paragraphs of the W3C's
Namespaces in XML Recommendation, is to allow XML processing applications to
recognize elements as being from different vocabularies.

It should be noted, however, that you can still apply this information in
any manner you want, and this application can certainly be schema-dependent.
This is entirely separate from what namespaces do.

Also, I would advise against saying "uniquely identifies elements". I think
"uniquely" and "identifies" are paired up a little too often in technical
literature, and in this case it is inaccurate. There is no guarantee that
two different namespaces won't identify the same element vocabulary.

Namespaces apply to element or attribute names only, and just further
classify classes (types/names) of elements. To say namespaces uniquely
identify elements is like saying you have uniquely identified me as a person
by saying I have the name Mike, in the namespace
'urn:anglicized-nicknames-for-judeo-christian-given-names'. Nothing unique
about that!

As always, someone tell me if I'm full of crap. Thanks.

   - Mike
____________________________________________________________________
Mike J. Brown, software engineer at            My XML/XSL resources: 
webb.net in Denver, Colorado, USA              http://skew.org/xml/