SOAML — MessageType Content Constraints

Summary:
A common and best practice pattern is to use portions of an abstract information model in messages. Due to the following constraint this is not allowed:

[4][1] All ownedAttributes of a MessageType must be PrimitiveType, DataType, ValueObject, or another MessageType or a reference to one of these types.
If followed, this constraint would require the complete information model to be <<MessageType>> or the information model to be remodeled as message types - both of these alternatives are unworkable and undesirable.
Suggested Resolution: Remove the constraint and make it part of the semantics of <<MessageType>> that any attributes or aggregated elements are passed by value.
Abstract information models will, invariably, have references. It should be up to the PSM mapping how references are handled. Of course on the web, references will be URIs.

Remove the ownedAttributes constraint of message type.