Your application would need to know the order. Given that there are no
standard notations at the moment, this doesn't seem unreasonable, as the
application needs to know what the notations mean, anyway.
If people "standardize" notations, this is a fair question. One quick hack
would be a NMTOKENS attribute that contained the names of the notation
attributes (or notations) in the order in which they were to be applied.
Or course, that attribute would need to be "standardized", too.
-- Ron Bourret