Overrides

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.

See Defining and nullifying JCL symbols and Using symbols in nested procedures for the complete set of rules for assigning values to symbolic parameters.