2.2.3 [NamespacesXML1.1] Section 8, Conformance of Processors

  • Article

C0004:

The specification states:

 To conform to this specification, a processor MUST report violations of 
 namespace well-formedness, with the exception that it is not REQUIRED to check 
 that namespace names are URI references [RFC3986].

IE9 Mode (All Versions)

Namespace names are not checked to be URI references.