I've posted two more chapters from Effective XML that address the proper design of markup:
I was inspired to put these up by an ongoing discussion on xml-dev about Microsoft's XAML vs. Mozilla's XUL. In my opinion, Microsoft gets some things right that XUL gets wrong, as these two chapters explain.
The IETF has posted a new draft of Internationalized Resource Identifiers (IRI). In brief, an IRI is like a URI that is not limited to ASCII. It can contain characters such as é and Θ.