> I'm not using a schema-aware stylesheet, but if I were using 
> a schema-aware stylesheet, the source document doesn't have a 
> DTD or XML schema associated with it.
> So am I correct in assuming that I would still have to use 
> the tokenize() solution?

Yes. I think you mentioned that it was an NMTOKENS in your post so I assumed
there was a DTD or schema.

Michael Kay
http://www.saxonica.com/