Ignore my question.. I missed part of it later on..
If there are both SPF and TXT records in the set and if they are not all
identical, return a "PermError".
Except for validation tools, I doubt there will be many implementations
would perform this check. Most will look for one type of record first and
only look for the other if the first one doesn't exist. This does lead to
some interesting behaviour if the records are not the same, but that is
something you as a publisher should take care of. Don't expect me to do
that for you. If you have published a parseable SPF record, I most
certainly won't query for a TXT record, let alone check if they are
identical.
Arjen