profileDesc: one or more catRef

I think this is another example of the Guidelines offering more than one way to do it. Almost any text will need more than one catRef/@target value: you can choose either to supply them all as the value of one @target attribute, or to supply them all as separate <catref> elements. Or indeed both. I'm not certain when to apply which strategy: I suppose the latter is more appropriate if you add some new classification methods to an existing text, or if the number of such classifications is really large, but neither seems like a strong argument. If we plump for either option as the only one recommended we will break some existing documents.

Oops. Now that I revisit this, I see that I misread section 2.4.3. For clarity, though, I propose revising "fall into more than one category" to say "fall into more than one category in a taxonomy". That is, you should have as many catRefs as there are taxonomies used. (When you use more than one category in a given taxonomy, you either use @target or you somehow manage to point to all of the categories using @target.)

After discussion, we agree that putting all targets on a single catref is not what we would recommend. Multiple catrefs with single targets also seems a bit extreme. So need to draft recommendation about stylistic preference.

Impelemented at revision 9915.