PTT ID, or Push-To-Talk ID, is a generic term for an ANI

Automatic number identification

Automatic number identification is a feature of telephony intelligent network services that permits subscribers to display or capture the billing telephone number of a calling party. In the United States it is part of Inward Wide Area Telephone Service . ANI service was created by AT&T for...

-like system used in Two-way radio

Two-way radio

A two-way radio is a radio that can both transmit and receive , unlike a broadcast receiver which only receives content. The term refers to a personal radio transceiver that allows the operator to have a two-way conversation with other similar radios operating on the same radio frequency...

 systems. It provides identification of the transmitting radio over the air, and is commonly used in Selective calling

Selective calling

In a conventional, analog two-way radio system, a standard radio has noise squelch or carrier squelch which allows a radio to receive all transmissions. Selective calling is used to address a subset of all two-way radios on a single radio frequency channel...

/signaling systems, usually in commercial and public safety radio systems.

PTT ID features are included in MDC-1200

MDC-1200

MDC , also known as Stat-Alert, MDC-1200 and MDC-600, is a Motorola two-way radio low-speed data system using audio frequency shift keying, . MDC-600 uses a 600 baud data rate. MDC-1200 uses a 1,200 baud data rate. Systems employ either one of the two baud rates. Mark and space tones are 1,200 Hz...

and other signaling systems.