Re: IDREFS

> DTDs have ID, IDREF, and IDREFS, but it does not have IDS.  At present,
> <list><key>...</key></list> is allowed.  Are there any reasons?

I think we could disallow lists of keys without causing problems.  If we 
did this, then we could delete the (keyList) rule in 7.4. The grammar in 
7.1 would also need modifying: I think it is just a matter of moving <key 
.../> from token to value.  On the other hand it seems a bit asymmetrical 
to support lists of <keyRef> but not lists of <key>.

James