IdSchemas/Existing MetaData

(work in progress)...

Metadata is the information used to describe schemas and elements, such as attributes, of schemas.

Most identity systems that have extensible schema implement a few types of metadata. Some of these are mandatory, without which the schema cannot be understood by the identity system.

There is also metadata on identity schema which is not implemented by identity systems themselves, but is descriptive and is useful for architects and schema designers.

Identity Systems with metadata of interest include:

* Information Card - see Claim Catalog * OpenID - see OpenID AX (metadata) * SAML 2.0 attributes and assertions * LDAPv3 * SPML v2.0 * XRI/XDI