[DM] 4.1.3 What is an xsd:QName?

In the second bullet point of 4.1.3 it is stated that a processing 
instruction returns an xs:QName but it has no namespace URI.

It seems to me that something that has no namespace URI may not be consistent 
with the definition of xsd:QName in W3C XML Schema. What is described in 
4.1.3 is half a tuple.

Andrew Watt