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If OSIDs define more functionality and interoperability than most of us need, how do we not spend resources developing unimportant stuff? OSIDs are broken down into small clusters of compliance (OsidSessions) that can be broken off and implemented one piece at a time. It usually requires a guiding hand to make sure that developers don't wander into areas not needed by the project.
How can OSIDs possibly define everything I need? It doesn't. OSIDs define the integration issues around many service domains along with some common data in these service domains. All of the "objects" are extensible in such a way that methods and data may be added outside its core specification. There's plenty of room to add your own stuff and have interoperability through the core specifications.
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