Actions:
A1: ServiceReference->ContainerReference
A2: SecurityRequirements to go (unclear what purpose is)
A3: Extensibility to be added
A4: Timestamp to be mandatory
A5: Activity only to be mandatory for initial records
A6: Relationship to other Activity Instance Docs
A7: Nature of "final" activity history purpose needs sorting out
A8: Andreas: How to do UR-ResourceUsage integration in XSD