The latest WG draft of this spec is rev 19, at http://docs.kantarainitiative.org/uma/draft-uma-core.html, as well as shown below in slightly less pretty form. This will shortly be submitted as a revised Internet-Draft to IETF as "rev 01". IETF rev 00 (WG rev 15) is here and here. The latest I-D can always be found here.
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