Action Code Security for Next Numbers (P0002)

We were discussing a key to a file and was wondering if it was assigned from the Next Numbers file (F0002). I looked at various system records using P0002 and finally determined it came from another source. However I am aware of the danger of inadvertently making a change in the P0002 as index fields can move while being viewed and the change could set other fields back it time. If I add Action Code Security to P0002 will it affect the Next Number server or does Action Code Security only apply to the interactive program that is named (P0002)?