DD statements

All parameters in the operand field of DD statements can be overridden by including in the input stream (following the EXEC statement calling the procedure) a DD statement with the notation //procstepname.ddname in the name field. procstepname refers to the job step in which the statement identified by ddname appears.

If more than one DD statement in a procedure is to be overridden, the overriding statements must be in the same order as the statements in the procedure.