Using symbols on certain JCL statements

You might need to specify symbols within JCL for each invocation of a started task. Consider the following statements for possible use of symbols:

DD statements
EXEC statements.

If DD statement keywords (or the positional parameters for UNIT and VOL=SER) are specified on a START command, the following DD statement is added to the JCL processed by the system:

//IEFPROC.IEFRDER DD keyword=value...

The added JCL either adds a DD statement (if an IEFRDER statement is not specified in the source JCL) or modifies an existing IEFRDER DD statement in the source JCL. The DD statement override allows you to determine the characteristics for one DD statement when you issue the START command.

The DD statement keyword parameters can be any keyword that is valid on the MVS™ JCL DD statement. The IEFRDER DD statement contains all of the DD keywords specified on the START command. For example:

START  ABLE.LOAD,DSNAME=MY.LOADLIB,DISP=SHR

creates the following DD statement:

//IEFPROC.IEFRDER  DD  DSNAME=MY.LOADLIB,DISP=SHR

Note: If you are overriding a dataset name in the cataloged procedure and the name of the data set is 44 characters long, use DSN=name. If you specify DSNAME=name, the START procedure stops and returns a JCL error.

Also, DD statement keywords can be specified on the START command for positional parameters on the DD statement in the procedure. For example:

START  CICS.CICS,333,U30PAK

is the same as:

START  CICS.CICS,UNIT=333,VOL=SER=U30PAK