Abbreviation for International Telecommunication Union–Telecommunication Standardization Bureau. The Telecommunications Standardization Sector of the International Telecommunication Union (ITU). The ITU-T is responsible for studying technical, operating, and tariff questions and issuing recommendations on them, with the goal of standardizing telecommunications worldwide. The ITU-T combines the standards-setting activities of two predecessor organizations formerly called the International Telegraph and Telephone Consultative Committee (CCITT) and the International Radio Consultative Committee (CCIR).