Proposed USA Standard (Data Communication Control Procedures for the USA Standarad Code for Information Interchange) CACM March, 1969 data communication, data communication control procedures, data communication establishment/termination procedures, data communication message transfer procedures, data communication error control procedures, data communication polling/selection procedures, communication, communication control procedures, communication establishment/termination procedures, communication message transfer procedures, communication error control procedures, communication polling/selection procedures, link, link control procedures, link establishment/termination procedures, link message transfer procedures, link error control procedures, link polling/selection procedures, data link, data link control procedures, data link establishment/termination procedures, data link message transfer procedures, data link error control procedures, data link polling/selection procedures 3.81 4.49 6.39 CA690305 JB February 20, 1978 9:09 AM 1922 5 1922 1922 5 1922 1922 5 1922