How to use Referbacks statement in JCL

A job that uses referbacks: //MM01AR    JOB   (36512),LYNCH,MSGCLASS=X,MSGLEVEL=(1,1), //              CLASS=A,NOTIFY=&SYSUID //STEP1   ...

A job that uses referbacks:

//MM01AR   JOB  (36512),LYNCH,MSGCLASS=X,MSGLEVEL=(1,1),

//             CLASS=A,NOTIFY=&SYSUID

//STEP1    EXEC PGM=TRANS

//TRANFILE DD   DSNAME=AR.TRANS.FILE,DISP=(NEW,KEEP),

//             UNIT=SYSDA,VOL=SER=MPS800,

//             SPACE=(CYL,(5,1)),

//             DCB=(DSORG=PS,RECFM=FB,LRECL=80)

//TRANERR  DD   DSNAME=AR.TRANS.ERR,DISP=(NEW,KEEP),

//             UNIT=SYSDA,VOL=SER=MPS801,

//             SPACE=(CYL,(2,1)),

//             DCB=*.TRANFILE

//STEP2    EXEC PGM=TRANSEP

//TRANIN   DD   DSNAME=*.STEP1.TRANFILE,DISP=SHR

//TRANOUT  DD   DSNAME=AR.TRANS.A.FILE,DISP=(NEW,KEEP),

//             UNIT=SYSDA,VOL=REF=*.STEP1.TRANFILE,

//             SPACE=(CYL,(5,1)),

//             DCB=*.STEP1.TRANFILE

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//STEP5    EXEC PGM=*.STEP3.LOADMOD

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