This material is covered in the HL7 specifications, it just doesn't have as much an impact on how the specification is written. And within different domains, these generalizations don't always apply. For example, most of PCC's early work was about data constraints (templates). And some HL7 domains focus very much on dynamic behaviours.
This is the real key to interoperability is to be able to operate with information recieved from outside your system. I think it should really be called outeroperability.