The System.Identity module exists to support applications such as directories that are concerned with storing, searching, and retrieving information (called claims) about physical and digital subjects and resources that can be uniquely identified.
At the highest level, the System.Identity schema is about entities called Parties that have PartyToPartyRelationships. Parties include People, Organizations, Groups, Devices, and Software Services. There are also special relationships called Roles that one party can play for another. Parties and Roles have IdentityKeys, or unique names in multiple dimensions issued by Authorities and described in Tokens. They also have (potentially multiple) Locations. Parties access Resources according to Policies. The instances in all these Extents can be specialized through a system of Kinds. In addition, Parties can be arbitrarily extended without schema changes through PartyAttributes. Because information about physical and digital subjects transcends conventional use in directory applications, federating subject and claim information to the code name “Oslo” repository is an important goal.