Nonstandard labels do not conform to the IBM or ISO/ANSI standard label formats. They are labels that you design. Your installation also must provide routines to write and process them. There are no requirements for the length, format, content and number of nonstandard labels, except that the first record on a tape cannot be a standard volume label recorded in EBCDIC, BCDIC or ASCII.

DFSMSrmm does not support nonstandard labeled tapes.

Nonstandard label routines are inserted into the control program by link-editing them into SYS1.LPALIB. Only an authorized system programmer can update SYS1.LPALIB. IBM recommends that you use SMP/E to link-edit.

If you use nonstandard tape labels and you want to use the DDR option, your system program must provide an exit routine to perform volume verification. The routine must be able to perform your verification within the first 48 bytes of any record in your nonstandard label. An LPA routine named NSLREPOS must be provided.

For detailed information about these and other available exit routines, see z/OS DFSMS Installation Exits.