A bit late in the discussion I realized that there is a potentially significant interface to initiatives in the area of semantic interoperability. a) The schemas mentioned here are derived from X.500/LDAP's object classes like InetOrgPerson. These schemas really suck when viewed from a modern data modeling perspective, because they fail to express more complex scenarios that anticipated in the standard. I propose to list a more modern schema like the Core Person Vocabulary as well. I remember that there was also an OASIS XML schema for Person and Organization with a solid model, but I cannot remember its name. b) Re Gap 5#: There are generic standards about how to manage metadata. One is the IOS/IEC 11179 (Part 3: Meta Data Registries can still be downloaded in the FDC version from the web for free: Google for (32N1983Ta-Text-for-ballot-FCD_11179-3.pdf"), another is the EU's Asset Description Metadata Schema. These models are pretty heavy, but they consider stuff that might be found out after some iterations of learning anyway, like multi-language support, geographical coverage, interoperability levels, metadata authority and change management. I suggest to name them at least as a background to check the scope and functionality of a new standards that is limited to identity attributes. I propose to add a sentence that references these to schemas as benchmark for a metadata registry for identity attributes. - Rainer