UCD elements

[Ray Plante]

On Thu, 1 Jul 2004, Martin Hill wrote:
> We will need (at latest when we introduce UCD2 over UCD1+)
> simultaneous UCDs of different versions in single metadata documents
> (so both older and newer tools can use them).

Okay, this is easily allowed in the column descriptions.

> So the former is simple to implement and will always work as long as
> UCDs can be represented as strings (is that not one of their
> requirements?), the latter 'correct' but quite horrible for
> developers?

I would generally agree with this statement (i.e. remove the last ?).
Whether the latter is 'correct' depends on exactly how you define the
different UCD XML Schemas.  I think enumerating all the different UCD
values is off the table for a number of reasons (ultimately I would
think that this would be up to the UCD WG, the presumptive
maintainers).  If your different UCD schemas is solely to differentiate
between the versions by element name, you gain nothing over the version
attribute technique.

cheers,
Ray