UCD elements

[Ray Plante]

On Thu, 1 Jul 2004, Matthew Graham wrote:
> I am inclined to agree with Guy and Ed that using appropriate namespaces
> is the way forward on this one.

This assumes that there is an xsd being defined for version 1 and 1+.  To 
date, we have neither, nor am I aware that there are plans to create them.  
Without them, it's not appropriate to use the XML Schema namespace 
mechanism. 

I think a simple, optional version attribute will be sufficient.  The 
value can be "1", "1+", etc.  Or if you need to be absolutely unambiguous 
(e.g. to prevent "1.0" from screwing things up) you use a URI as the 
value (e.g. "http://www.ivoa.net/ucd/v1+").

cheers,
Ray