T.51/ISO/IEC 6937
T.51 / ISO/IEC 6937:2001, Information technology — Coded graphic character set for text communication — Latin alphabet, is a multibyte extension of ASCII, or more precisely ISO/IEC 646-IRV. It was developed in common with ITU-T (then CCITT) for telematic services under the name of T.51, and first became an ISO standard in 1983. Certain byte codes are used as lead bytes for letters with diacritics.