Talk:Draft Appendix: ITS R1.1 Extensibility Implementation Considerations

IMO, Extensibility should be an accepted and promoted concept defined within the HL7 Modeling and represented visually and captured within the MIF. The ITS specs should only describe how the extensibility concept is defined in the ITS. I agree, there are strick conformance rules the foremost of which is that receivers not understanding extensions must ignore. In practice, parties will agree prior to messaging each other whether or not they will exchange extensions. Extensions is a natural mechanism to allow vendors and implementers a chance to demonstrate features that add value, are compelling to their implementations and may one day find their way into the specifications. Without extensibility, vendors competing in a market, but forced to adopt standards have little hope of adding value and differentiating themselves from their competitors. It's important to recognize and endorse and model the concept of extensibility and not leave it as an implementation detail in the ITS currently in fashion.