The United Nations specialised agency dealing with telecommunications. At present, there are 164 member countries. One of its bodies is the International Telegraph and Telephone Consultative Committee, CCITT. A Plenary Assembly of the CCITT, which takes place every few years, draws up a list of “Questions” about possible improvements in international electronic communication. In Study Groups, experts from different countries develop “Recommendations” which are published after they have been adopted. Especially relevant to computing are the V series of recommendations on modems (e.g. V.32, V.42), the X series on data networks and OSI (e.g., X.25, X.400), the I and Q series that define ISDN, the Z series that defines specification and programming languages (SDL, CHILL), the T series on text communication (teletext, fax, videotext, ODA), and the H series on digital sound and video encoding.