Tim Bray, author of the Namespace spec, enlightens us here that I am technically wrong by using the term "empty namespace". Yes. Absolutely. But the "not member of any namespace" vs. "member of the empty namespace" distinction becomes meaningless once you start coding against an XML infrastructure, because in the programming models, there is pretty much always a namespace qualifier. In the .NET Framework, for instance, the NamespaceURI is an empty string in such cases (... and it should really be null).