Automated Position Reporting. Used in Ship Reporting Systems. Not used in MASTREP or REEFREP which rely on AIS.

Automatic Radar Plotting Aid. An automatic radar plotting aid that complies with IMO regulations.

Automatic Retransmission Request. A NBDP (telex) technique for detecting and correcting transmitted errors, requiring an automatic transmitted response from the receiving station. Communications are limited to a single transmitting and a single receiving station.

American Standard Code for Information Interchange. A popular code for the exchange of information between computers, computer terminals and other data applications.

Aid To Navigation.

Built–in Integrity Test. Used in AIS equipment.

Binary Digit. One of the digits 0 or 1 used in binary notation. It is the basic unit of information in computers, data processing or digital communications.

Built–in Test Equipment. Used in radio and other electronic equipment.

A group of bits taken together and treated as a unit in computers, data processing or digital communications. Typically one byte consists of 8, 16, 32, 64 or 128 bits, depending on the technology.

The Consultative Committee on International Radio (Replaced by the ITU–R). Formulated new technical standards for radio equipment and the recommendations on the use of radio spectrum.