(a) The term “automatic number identification service” means an access signaling protocol in common use by common carriers that uses an identifying signal associated with the use of a subscriber's telephone to provide billing information or other information to the local exchange carrier or any other interconnecting carriers.
(b) The term “blocking” means a service that allows the originator of a call to prevent or control the transmission of information that identifies the originator to the recipient of the call.
(c) The term “caller identification” means the transmission of information that identifies the originator of a communication to the recipient of the communication via an electronic signal which is decoded by a customer provided display unit which displays, records or forwards the caller's telephone number or other identifying information. Such term shall not include:
(1) An internal office system, including but not limited to, a centrex or private branch exchange (PBX) system or virtual private network;
(2) An identification system used for emergencies, such as an emergency telephone line used by a public agency or a 911 emergency telephone service;
(3) Any identification service provided with legally sanctioned call tracing or tapping procedures; or
(4) Any automatic number identification service or technology.