You use the authority (AUT) parameter in create, grant, and revoke commands.
The authority (AUT) parameter specifies the authority granted to all users of an object. It also specifies an authorization list that is used to secure the object. Four object types allow the AUT parameter to contain an authorization list: LIB, PGM, DTADCT, and FILE. Public authority is an i5/OS™ object attribute that controls the base set of rights to that object for all users having access to the system. These rights can be extended or reduced for specific users. If you specify an authorization list, the public authority in the authorization list is the public authority for the object. The owner of an object has all authority to the object at its creation.
If the object is created as a private object or with the limited authority given to all users, the owner can grant more or less authority to specific users by specifically naming them and stating their authority in the Grant Object Authority (GRTOBJAUT) command. The owner also can withdraw specific authority from specific users, or from all users (publicly authorized and/or specifically authorized) by using the Revoke Object Authority (RVKOBJAUT) command or the Edit Object Authority (EDTOBJAUT) command.