Clearly state that a Data message cannot include both a container ID and a type ID
Right now, the documentation:
Mentions that "For each object, either typeid or containerid must be specified". However, it does not clearly state that you CANNOT include both in a data message, even if either the typeid or containerid is null (and the other is non-null). It's a minor distinction, but it helps prevent folks from trying to create a base class for a data message that includes both a typeid and containerid.