The datamodel can be bound differently. Then there should be mapping btw that data model and various protocols. Security and protocols. 2.4 exclude application level security. We have interaction with seciruty at transport or application.
Security has to be in the datamodel.
We said that the key to evolvability and multiple intermediaries is the combination of an abstract data model with a protocol parameterization. Many members were interested in this. Yes so that we can bookmark it. Unlike SOAP we need that XP is more transport neutral. You may have chicken and egg pb when you resolve and get entities.