If you are deleting a cataloged non-VSAM data set, the entry for the data set in the system catalog is removed when the system obtains the volume serial number from the catalog. When the volume serial number is coded or referenced on the DD statement, the data is deleted but its entry remains in the catalog.
If an error occurs while the system is deleting a cataloged data set, its entry remains in the catalog. The data set itself is or is not deleted, depending on when the error occurs.
To delete an entry from a catalog, use the DELETE command as described in z/OS DFSMS Using Data Sets. Using the DELETE command makes the space occupied by the data set available for reallocation. To delete catalog entries for data sets that are not cataloged in a catalog, use the UNCATLG statement of IEHPROGM as described in z/OS DFSMSdfp Utilities.