Scenario1 - Defines a PDS on single volume.

Code -

----+----1----+----2----+----3----+----4----+----5----+
//MATEPKP  JOB (123),'MTH',CLASS=A,MSGCLASS=A,MSGLEVEL=(1,1), 
//             NOTIFY=&SYSUID 
//* 
//STEP01   EXEC PGM=IEFBR14 
//DD1      DD DSN=MATEPK.TEST.PDS,
//            DISP=(NEW,CATLG,DELETE), 
//            SPACE=(TRK,(10,10,10),RLSE),
//            UNIT=SYSDA,VOLUME=SER=DEVHD4,
//            DCB=(DSORG=PO,RECFM=FB,LRECL=80,BLKSIZE=800)

Scenario2 - Defines a PDS on multivolume with volume count.

Code -

----+----1----+----2----+----3----+----4----+----5----+
//MATEPKP  JOB (123),'MTH',CLASS=A,MSGCLASS=A,MSGLEVEL=(1,1),
//             NOTIFY=&SYSUID
//*  
//STEP01   EXEC PGM=IEFBR14 
//DD1      DD DSN=MATEPK.IEFBR14.PDS, 
//            DISP=(NEW,CATLG,DELETE), 
//            SPACE=(TRK,(10,10,10),RLSE),
//            UNIT=SYSDA,VOLUME=(,,,3,SER=(DEVHD2,DEVHD3,DEVHD4)), 
//            DCB=(DSORG=PO,RECFM=FB,LRECL=80,BLKSIZE=800)

Scenario3 - Defines a PDS without volume information.

Code -

----+----1----+----2----+----3----+----4----+----5----+
//MATEPKP  JOB (123),'MTH',CLASS=A,MSGCLASS=A,MSGLEVEL=(1,1),
//             NOTIFY=&SYSUID
//*   
//STEP01   EXEC PGM=IEFBR14 
//DD1      DD DSN=MATEPK.IEFBR14.PDS,
//            DISP=(NEW,CATLG,DELETE), 
//            SPACE=(TRK,(10,10,10),RLSE), 
//            UNIT=SYSDA,
//            DCB=(DSORG=PO,RECFM=FB,LRECL=80,BLKSIZE=800)

Explaining Example -

System assigns default volume to store the dataset.

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