a service that provides access to descriptions of resources. an authority identifier managed by a registry. Typically, this means the AuthorityIDs that originated (i.e. were first published by) this registry. Currently, only one registry can lay claim to an AuthorityID via this element at a time. a naming authority; an assertion of control over a namespace represented by an authority identifier. the organization that manages or owns the this authority. In most cases, this will be the same as the Publisher.