Expanded name/URI for xml: namespace?

Subject: Expanded name/URI for xml: namespace?
From: "John E. Simpson" <simpson@xxxxxxxxxxx>
Date: Sat, 09 Sep 2000 14:06:58 -0400
Section [5/4] in the XPath spec begins:

   Each element has an associated set of namespace nodes, one for
   each distinct namespace prefix that is in scope for the element
   (including the xml prefix, which is implicitly declared by the
   XML Namespaces Recommendation) and one for the default namespace
   if one is in scope for the element.

My question pertains to that parenthetical aside: Does this imply that the xml prefix is by default in scope for any XML document? (Not counting documents which have an xmlns="" attribute; per the note in this section, "An attribute xmlns='' 'undeclares' the default namespace.")

If this is the case, what is the expanded name of this namespace node? I've searched several resources, including the namespaces Rec, XML-DEV archives (to the extent possible), this list's archives, Mike Kay's book, and so on, and have (interestingly!) found no sign of a URI which is mapped to the xml: prefix. (Some older messages on XML-DEV, prior to the final Namespaces Rec, mention xmlns:xml="http://w3.org"; but that seems spurious or at least just intended for illustrative purposes.) Is there one? Should there be, in a compliant (=XPath-aware) processor?

Any guesses (or preferably, certainties :)?

======================================================================
John E. Simpson         | "I used to be an airline pilot. I got fired.
http://www.flixml.org   | I kept locking the keys in the plane. They
simpson@xxxxxxxxxxx     | caught me on an 80-foot stepladder with a
                        | coathanger." (Steven Wright)


XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list



Current Thread