Stephen, Donal and others, please see my comments interweaved below.

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What is the difference between xsd:QName and xsd:NMTOKEN? We've changed things over to xsd:NMTOKEN. It's easy to change to xsd:QName but I think we need to know why.

xsd:QName is a qualified XML name in respect that its local name part is of type xsd:NCName and allows for a namespace qualifier (like jsdl). It is thus a xsd:NCName extension (that doesn't allow for whitespaces either) with the optional ':' to form something like "jsdl:storageUnits". I suppose xsd:QName is not needed for enumerations that we do not want to be extended by users (i.e. jsdlVersion). Since xsd:NMTOKEN allows for characters, digits, ".", ":" and "-", it forms IMHO a superclass (in terms of power, not formal inheritance) of xsd:QName. Cheers, Michel