When someone says, "you need to APF authorize this dataset", what do they mean?
Well, APF means "Authorized Program Facility". In a z/OS environment, APF is a facility that permits the identification of programs that are authorized to use restricted functions.
To find the datasets that are APF authorized:
1. Type TSO ISRDDN in your ISPF session (some shops need just ISRDDN with no TSO prefix) and hit enter.
2. Type APF and hit enter. It'll bring up a list of all datasets that are APF authorized.
Remember that, if you like to use a APF authorized dataset in a job STEPLIB, make sure all the datasets in the STEPLIB are APF authorized.