Permissible Interference: Observed or predicted interference which complies with quantitative interference and sharing criteria contained in RR or in ITU recommendations or in special agreements.
Accepted Interference: Interference at a higher level than that defined as permissible interference and which has been agreed upon between two or more administrations without prejudice to other administrations.
Harmful interference: Interference which endangers the functions of radionavigations service or of other safety services or seriously degrades, obstructs, or repetadly interrupts a radiocommunication service operating in accordance with RR.
Note: The terms "permissible interference" and "accepted frequence" are used in the coordination of frequency assignments between administrations.