The purpose of the Organization/Actor catalog is to capture a definitive listing of all participants that interact with IT, including users and owners of IT systems.
The Organization/Actor catalog can be referenced when developing requirements in order to test for completeness.
For example, requirements for an application that services customers can be tested for completeness by verifying exactly which customer types need to be supported and whether there are any particular requirements or restrictions for user types.
The Organization/Actor catalog contains the following metamodel