A value you assign to a symbolic parameter on a SET statement is overridden by:

• A subsequent SET statement
• Any default value assigned or nullified on a subsequent PROC statement for a procedure
• Any value assigned or nullified on a subsequent EXEC statement that calls a procedure.

When the target of an MVS™ START command contains a JOB statement, and the MVS START command specifies symbolic parameters, the system inserts a SET statement into the job to define those symbolic values. In contrast to the normal behavior of SET statements, values defined on this SET statement override:

• Other SET statements that occur before the first IF or EXEC statement in the job
• An EXEC statement that invokes an outer (non-nested) procedure
• A PROC statement in an outer procedure.