The International Telecommunication Union Telecommunication Standardization Sector (ITU-T) is one of the three sectors of the ITU. The ITU is the United Nations specialized agency in the field of telecommunications. ITU-T is responsible for studying technical, operating and tariff questions and issuing Recommendations on them with a view to standardizing telecommunications on a worldwide basis.
The World Telecommunication Standardization Assembly (WTSA), which meets every four years, establishes the topics for study by the ITU T study groups which, in turn, produce Recommendations on these topics. The WTSA is responsible for the approval of the ITU-T Recommendations.