If the STORE function is requested for an existing collection name or is requested after the new collection name MVS catalog entry has been defined, the actual storing of the object is completed. The initial storage class and management class assignments are stored in the directory entry created for the object. The initial class assignments are determined as follows:

• If the management class and storage class are not specified on the OSREQ Store request, the default assignments contained in the MVS catalog entry for the collection are used as the assignments for the object.
• If management class and storage class are specified in the OSREQ Store request, the names are provided to the ACS routines, which either confirm or override the assignments as the initial storage class and management class assignments for the object.
• If storage class is specified without management class, the storage class name is provided to the ACS routines, which either confirms or overrides the assignment, and then determines the initial management class assignment for the object.
• If management class is specified without storage class, the ACS routines determine the initial storage class assignment. The management class name is provided to the ACS routines, which either confirms or overrides the management class assignment.