The Sender and Receiver elements (8.5.2.1 & 8.5.2.2) each need a Type attribute to match the To and From elements. This is necessary since there may be multiple PartyId elements in a single TraceHeader. As with To and From, the Type should default to URI. Add another paragraph to 8.5.2.1.1: The PartyId MAY have a single type attribute (see section 8.4.4.1). Regards, David Fischer Drummond Group. Ian, do you still want each issue in a separate eMail?