Eclipse validation - dtd? namespaces?

[samtherobot]

I'm definitely not an expert on XML, dtds and namespaces but I'm trying to figure out how to develop better with Eclipse.

Joomla 1.5 of course uses special tags (<JDOC:include />) in templates for the content. Eclipse doesn't like this (using PDT & Aptana) and give the warnings of "Unknown tag". Would the solution to this be to have a dtd declaration for joomla templates? Is there one already created?

As a sidenote, anyone know where the J!Code project is at? Seems kinda dead but it's a great idea (although I'd like to see it in PDT, oh well).