Protocols and standards
ITU-T
Acronym: UIT-T
ITU-T is the telecommunication standardisation sector of the International Telecommunication Union, a specialised agency of the United Nations.
It is the body publishing the recommendations designated by a letter and a number: T.30 for negotiation between fax machines, T.38 for carrying them over IP, E.164 for numbers. These texts carry no force of law, but their adoption by manufacturers makes them binding in practice: a machine that departs from them talks to nobody.