Thanks George, I'll take a look at http://www.w3.org/TR/xmlschema-1/#cos-nonambig ... still trying to wrap my head around this stuff(!) I wanted to experiment with extending XHTML using Mr. Clark's modularization - if I have to go on an 'ambiguity hunt', I might end up (re)writing the entire schema ...

Hi, I've been experimenting with James Clark's XHTML Modularization: http://www.thaiopensource.com/relaxng/xhtml/ I downloaded the relaxng schema and validated a *simple* xhtml document against it in Oxygen 6.2. It validates no problem. So far so good. I then convert the relax ng schema to a W3C XML...