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This scenario uses classic UMA. See the swimlane diagrams for details. A YouTube video provides a demo of sample apps, showing how the individuals in question might experience these processes.
Solution Demo
The UMA group's Google TechTalk video from February 2012 demonstrates how the SMARTAM authorization service could be used to provide subscription request workflows. (Note that it uses old UMA terminology: authorization manager, host, and requester rather than authorization server, resource server, and client.)