See the User Function Registration APIs to add, change and/or retrieve function usage information.
Be aware that this is not quite a "security" function; it is simply a registry of information. The system does not enforce the settings you add there. Applications may use this registry for any purpose, or they may ignore it entirely. If an application does not read these entries, then the application will not enforce the rules.
Some IBM applications (e.g., the Navigator and most iSeries Access functions) will read this registry and obey. A 3rd-party ODBC driver for example might or might not; ask the vendor.
This is really intended for your own applications.