The Full Form of CCITT is Consultative Committee for International Telephony and Telegraphy.

The CCITT is part of the ITU (International Telegraph Union), which has a history that stretches back to 1865. In that year, 20 countries agreed to standardize telegraph networks. The ITU was set up as part of the agreement to work on subsequent amendments. In subsequent years, the ITU got involved with telephony regulation, wireless radiocommunications, and sound broadcasting. In 1927, the union was involved in allocating frequency bands for radio services, including fixed radio, mobile radio (maritime and aeronautical), broadcasting, and amateur/experimental radio. In 1934, the union changed its name to the International Telecommunication Union to more properly define its role in all forms of communication, including wire, radio, optical, and electromagnetic systems.

After World War II, the ITU became a special agency of the United Nations and moved its headquarters to Geneva. Also at this time, it made mandatory the Table of Frequency Allocations, which allocates frequency bands for each radio service. This table is meant to avoid interference between aircraft and ground communications, car telephones, maritime communications, radio stations, and spacecraft communications.

Then, in 1956, two separate ITU committees, the CCIF (Consultive Committee for International Telephony) and the CCIT (Consultive Committee for International Telegraphy) were joined to create the CCITT to more effectively manage the telephone and telegraph communications.

In 1993, the ITU went through a reorganization. The ITU-T is the ITU’s Telecommunications Standardization Sector. Two other main sectors formed at this time were the Radio communications Sector (ITU-R) and the Telecommunications Development Sector (ITU-D). The CCITT was integrated into this new structure.

Even though the ITU-T now creates recommendations and standards, the CCITT recommendations are still mentioned quite frequently, but they should be referenced as now being managed by the ITU.