1. A method for use by an apparatus of a communication network, the method comprising: detecting that a user or user equipment attaching to the communication network belongs to a usage group, based on group identity information that is allocated to the user or user equipment and identifies the usage group; detecting, based on the group identity information, whether or not a first rules function out of several rules functions has been allocated to another user or user equipment of the usage group; and in case it is detected that the first rules function has been allocated to another user or user equipment of the usage group, selecting, for the user or user equipment, the first rules function.