Under the iSeries system ip address, click on:
Expand Intergrated File Systems
Expand the library you want to work with
Right click on object and select Permissions
Click on Authorization List and select there to add then apply
Almost there but the autl doesn’t take affect until you change *PUBLIC to *AUTL.
…Assuming, of course, that *PUBLIC *AUTL is what is wanted. That is a very reasonable assumption that probably applies to the vast majority of uses. But it might be faster simply to set *PUBLIC *EXCLUDE directly on the object if that’s what the *AUTL is also going to say anyway. You might decide that all authorities will be assigned via *AUTL as a standard because authorities can be changed on the *AUTL without requiring a lock on the object being secured, and that can be a significant advantage.