To register a product, issue the Register service. See Using the Register Service. When a product calls the Register service, MVS™ determines, based on the register request and the enablement policy defined in IFAPRDxx, whether or not the product is enabled to run on the system.

If the Register request type and the policy entry indicate that the product can run on the system, MVS registers the product as one that is running. Other products can then use the Query_Status and List_Status services to check whether your product is running. The system and other products assume that a product that is registered is a product that is running on a particular system.

Thus, it is important that, when your product finishes processing, it issue the Deregister service to tell MVS that it is no longer running. See Using the Deregister Service.