//SMSDS3  DD  DSNAME=MYDS3.PGM,DATACLAS=DCLAS03,DISP=(NEW,KEEP),
//          SPACE=(128,(5,2)),AVGREC=K

In the example, the space allocation defined in the DCLAS03 data class is overridden by the SPACE and AVGREC parameters, which indicate an average record length of 128 bytes, a primary quantity of 5K (5,120) records, and a secondary quantity of 2K (2,048) records.

//SMSDS3A DD  DSNAME=MYDS3.PGM,DATACLAS=DCLAS03A,DISP=(NEW,KEEP),
//          AVGREC=K

In the example, the space allocation defined in the DCLAS03A data class is overridden by the AVGREC parameter, which indicates that the primary and secondary quantity represents thousands of records.