The CCITT, considering that the telex network is well adapted for the economical transmission of data at fairly slow speeds, for the equipment required for binary transmission of data by telex stations, over and above the normal equipment, is relatively simple.
ITU-T S.15 FRENCH-1988 Referenced Document
ITU-T F.60 Operational Provisions for the International Telex Service (Study Group I) 34 pp*， 1992-01-01 Update
ITU-T U.1 Signalling Conditions to Be Applied in the International Telex Service*， 1993-03-01 Update
ITU-T U.21 Operator Recall on a Telex Call Set up on a Radiotelegraph Circuit - Telegraph Switching (Study Group IX) 1 pp*， 1989-01-01 Update
ITU-T U.22 Signals Indicating Delay in Transmission on Calls Set up by Means of Synchronous Systems with Automatic Error Correction by Repetition - Telegraph Switching (Study Group IX) 2 pp*， 1989-01-01 Update