ITU-T recommendation T.50 specifies the International Reference Alphabet (IRA), formerly International Alphabet No. 5 (IA5), a character encoding. ASCII is the U.S. variant of that character set.
Contents
The original version from November 1988 corresponds to ISO 646. The current version is from September 1992.
History
At the beginning was the International Telegraph Alphabet No. 2 (ITA2), a five bits code. IA5 is an improvement based on seven bits bytes.
- V.3 IA5 (1968) Initial version, superseded
- V.3 IA5 (1972)
- V.3 IA5 (1976-10) Superseded
- V.3 IA5 (1980-11) Superseded
- T.50 IA5 (1984-10) Superseded
- T.50 IA5 (1988-11) Superseded
- T.50 IRA (1992-09) In force
Use
This standard is referenced by other standards such as RFC 3966.
It is also used by some analog modems such as Cisco ones.
This standard is referenced by other standards such as RFC 3939 - Calling Line Identification for Voice Mail Messages.
Standardisation
References
ITU T.50 Wikipedia(Text) CC BY-SA