Requesting multiple-level Muenchian examples or explan

Hi.

My question pertains to the Muenchian trick to group XML records by unique
values when the secondary key is optional (in other words it doesn't
necessarily appear in each record).

I have a large amount of xml I wish to sort and group on two keys (named
keyword and keyword02). I have successfully managed to sort and group the
data on keyword, which appears in every record. But I cannot get the data to
then sort and group on keyword02 - which does not appear in every record.

I understand that to add multiple levels with the Muenchian trick, you must
concatenate the first and second keys to make a unique key, but when I try
it the second level is simply not processed. Does the multi-level logic work
when the second key is optional?

I do know this would be easier to do in XLST 2.0, but that is not currently
an option.

Could anyone offer links or examples as to how to sort and group on 1
permanent key and 2 (or more) optional keys?
I've already examined :
	http://www.jenitennison.com/xslt/grouping/muenchian.html (great
articles by the way)
	http://www.biglist.com/lists/xsl-list/archives/ (many searches on
grouping, Muenchian, sorting, ...)
	http://www.dpawson.co.uk/ (specifically: Sorting, Grouping, Sorting
& Grouping)
	and http://www.netcrucible.com/xslt/msxml-faq.htm

Thank you.
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Rebecca Downey rdowney@xxxxxxxxxx
Give us the money. You get the truck. No one gets hurt.
- Hummer Ad
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list