START command processing when the member is a job

If a JOB statement is the first statement in the member, the system uses the JCL provided in the member. For example, given the following JOB statement and JCL in the INIT member:

//INIT     JOB    'accounting_info',MSGLEVEL=1
//JESDS    OUTPUT JESDS=ALL,OUTDISP=(PURGE,WRITE)
//INIT     EXEC   INIT
//DD1      DD     DSN=SYSTEM.ACCOUNT.DATA,DISP=SHR
//*

JES2 automatically issues the command S INIT.INIT,,,JES2,SUB=JES2 and the preceding JCL is invoked, starting the MVS™ initiator by calling the INIT procedure. The S INIT.INIT,,,JES2,SUB=JES2 command now uses the source JCL and invokes the same procedure.