Jeni's Musings

Thanks for the pointer to CURIEs. They deal with the problem of non-Name relative URIs, but I still dislike that they use normal XML namespace declarations to provide base URIs.

Say that I’m writing some XSLT 2.0 that produces some XHTML+RDFa. For the type declarations that I use in the XSLT 2.0, I have to declare the XML Schema namespace http://www.w3.org/2001/XMLSchema. For the CURIEs in RDFa, I have to declare the XML Schema base URI `http://www.w3.org/2001/XMLSchema#’. So I end up with two different namespace declarations with two different prefixes:

xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:rdfxs="http://www.w3.org/2001/XMLSchema#"

It’s plain confusing to have two very subtly different URIs floating around, both termed “namespaces”, both referring to the same thing.

Of course you don’t run into this problem if you design namespace URIs such that they end with a slash or a hash, but lots of XML namespaces don’t follow those rules. XML Schema is the most glaring example because it’s actually used quite a lot in RDF to get datatyping.