A PBX system with a shared line connected to a plurality of telephone devices includes one or more processors that control a connection for an incoming call from a caller, the one or more processors being operable to access a listing that includes one or more callers or calling numbers designated as private to a first telephone device. The one or more processors being further operable to send an alert to only the first telephone device in the event that the one or more callers or the calling numbers in the listing includes a caller or calling number associated with the incoming call. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.