I notice that Role is still not a required element in the
ebMS header.
I would like the schema to require its use as unnecessary interoperability
problems can be avoided by requiring the element.
Also, when ebMS is used with CPPA (and when CPPA is
connected with BPSS), it promotes integration by including the Role element.
If the CPPA and BPSS are not used, it is easy to just
default Role to something like Requester or Responder.