The W3C has released a new Last Call Working Draft of Namespaces in XML 1.1.

Like its predecessor, this draft makes as few substantive changes to the original Namespaces in XML as possible. The changes to namespace processing specified by this document apply only to XML 1.1 documents, further limiting its scope. The mechanism for undeclaring namespaces and the binding of the xmlns prefix to the URI reference "http://www.w3.org/2000/xmlns/" are preserved in this draft.

More substantively, this draft moves from using Uniform Resource Identifier (URI) references to Internationalized Resource Identifier (IRI) references. Section 7 of the draft explores some limitations of IRI references, but generally IRI references will simplify the comparison of identifiers which contain characters beyond the ASCII range. While the empty string is a legal IRI reference, it is prohibited from use as a namespace identifier.

This draft also adds a clarification that local names should not begin with "XML", "xml", or any case-variation thereof, though it stops short of explicitly reserving those names. It also makes explicit how namespace identifiers should be compared:

"[Definition: IRI references which identify namespaces are considered identical if and only if they are exactly the same character-for-character.] Case differences and escaping differences (including case differences in escape sequences) are therefore significant. Note that IRI references which are not identical in this sense may in fact be functionally equivalent."

Related stories:

• W3C releases Namespaces in XML 1.1, Requirements
• XML 1.1 Working Draft Published