Customising XHTML

Zeldman's A List Apart has published a series of articles on creating a custom DTD for XHTML.

Starting with Peter-Paul Koch article JavaScript Triggers which uses custom attributes to create javascript triggers.

This article was then quickly followed up by J. David Eisenberg's article Validating a custom DTD, exploring how to use Koch's code and still keep the page validating.

Most recently the W3C Quality Assurance Team have published an article, More about custom DTDs, to discuss the matter further - including the downside of creating a custom DTD which they argue breaks the spirit of XHTML and therefore the main reason you'd want to validate the document. Instead the suggest creating a "Creating a custom markup language with the modularization of XHTML" and suggest the following article from Shane McCarron, How to create XHTML Family modules and markup languages for fun and profit, as a starting point.

I must admit all this (like bitwise operators) is a bit of a blind spot for me - I'm hoping that these articles will help no end.