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Document the used version of the specification
Always choose the latest version of the specification when starting the process of developing a new 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.
Be aware that it is a very unlikely event that all applications migrate their implementations at the same time to a newer version of the specification.
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