A preprocessing directive may be placed in a parameter which can then be referenced by a command, notify or notes list. When the job runs, the parameter is resolved and it's result is then resolved where the preprocessor directive is in the job.
Example: The following preprocessor directive containing a variable named account is place in the first parameter slot.
The first parameter p1 is referenced in the Job commands
year_end_report ((p1))
When the job's processed commands are previewed, it shows the contents of the variable "account" which is "z19080".
year_end_report z19080
The first pass evaluates the commands and the second pass resolves the preprocessor directive in the parameter.