Thanks for all your suggestions ,
I certainly have learned a lot from all your examples and I will indeed try
to move from DTD to RELAX-NG.
Sadly the current XML editor we use doesn't support anything other than XSD
and after some quick tests it doesn't even seem to support XSD 1.1.
A quick fix would be to follow Sandor's advice and just convert the
attributes to elements. The long term being trying to look into better XML
Authoring software.
Thanks again for all your detailed explanations and suggestions.
Graeme
