International Telecommunications Union - (ITU) – The ITU is a charter organization of the United Nations (Geneva, Switzerland).  The ITU is a formal worldwide body that defines standards for telegraphic (including television) and telephone equipment. It's the parent organization for ITU-T (formerly CCITT) and ITU-R (formerly CCIR).

ITU-TSS - (International Telecommunications Union-Telecommunications Standardization Section) - International standards organization charged with setting standards for telecommunications. It's also denoted as ITU-T. See CCITT.