This Recommendation defines the character coded control functions and their coded representation for use in 7-bit and 8-bit coded ITU-T Telematic services and related to the text communication part of the Telematic services.

The control functions contained in this Recommendation define the basic meanings which may be common in some (or all) of the Telematic services. The definitions of the control functions are aligned to those in ISO/IEC 6429 and ISO/IEC 10538 where possible with the exception of some specific functions defined by particular services.

This Recommendation specifies control functions to handle bi-directional texts in character-imaging devices. The bi‑directional concept is an addition to the uni-directional device concept which was the base for the former ITU-T Recommendations | ISO standards. It means that the control functions which were modified to meet the bi-directional requirements can be used for uni-directional devices, as before.