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When you are developing an implementation, make sure that you have a clear understanding of the specification of the protocol and the artefact. The specification is meant to be precise enough to ensure that your implementation is interoperable with others or is at least very close to be. In case of questions or unclarities, do not consciously make assumptions but contact the author of the specification. Interoperability is primarily a matter of correct and consensual interpretation of this specification. Assumptions made that are not shared amongst the community of implementers difficult the will imped a proper implementation and will require (costly) software adaptations. adaptations in a later stage in the software development lifecycle, with a higher cost.
Take into account the that the intended audience of the specification is wide. Knowing that product managers, end-users, test developers or product developers not always fully share the author’s background and expertise, be aware that interpretation mistakes or liberties will abound.
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Always choose the latest version of the specification that will be used for the implementation. Document the version number and make this information accessible for the end-users. Not doing so will cause misunderstandings and interoperability issues over time. Providing the user with clear information about the version and revision numbers of both the implementation and the implemented specification will help to avoid this.
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When migrating your implementation to a newer version of the specification, make sure that you have identified and implemented the non-backward compatible features of the specification. This is needed to be able to correctly consume artefacts produced by other applications/implementations using the older version(s) of the specifications.
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