If the OSREQ Store request specifies a new collection name, an MVS catalog entry is created for the collection. The MVS catalog entry contains the names of the management class and storage class to be used as default assignments for objects added to the collection. The management class and storage class names are determined by the ACS routines as follows:

• If storage class and management class names are not specified in the OSREQ Store request, the ACS routines determine the storage class and management class names to be used as the default assignments for the collection.
• If storage class and management class are specified in the OSREQ Store request, the names are provided to the ACS routines, which either confirms or overrides the assignments as the default storage class and management class assignments for the collection.
• 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 default management class assignment for the collection.
• If management class is specified without storage class, the ACS routines determines the default storage class assignment. The management class name is provided to the ACS routines, which either confirms or overrides the management class assignment.