I get the impression that Dale's interpretation is slightly
different from Chris'. If the duplicateElimination attribute
is set to "always" in the CPA, and no DuplicateElimination
element is present in the message header, Dale's
interpretation would return an "inconsistent" error whereas
Chris' interpretation would say that the receiver should
eliminate duplicates as indicated in the CPA.
My assumption has been that those message characteristics
that can be made to have "per message" semantics always
have to be explicitly stated in the message header (and they
have to be consistent with the CPA) before they take effect.
Therefore, I vote for Dale's interpretation.
-Arvola