KOI-8
KOI-8 (КОИ-8) is an 8-bit character set standardized in GOST 19768-74. It is an extension of KOI-7 which allows the use of the Latin alphabet along with the Russian alphabet, both the upper and lower case letters; however, the letter Ёё and the uppercase Ъ are missed, the latter to avoid conflicts with the delete character (both are added in most extensions, see KOI8-B). The first 127 code points are identical to ASCII with the exception of the dollar sign $ (code point 24hex) replaced by the universal currency sign ¤. The rows x8_ and x9_ (code points 128–159) might be filled with the additional control characters from EBCDIC (code points 32–63).
| Language(s) | Russian (basic support) |
|---|---|
| Standard | GOST 19768-74 |
| Classification | Extended ISO 646, KOI |
| Extensions | KOI8-B (KOI8-R, KOI8-U, KOI8-RU, KOI8-T, ISO-IR-111, KOI8-F) |
| Transforms / Encodes | ISO 646:IRV (lower) KOI-7 N1 (upper) |
| Preceded by | KOI-7 |
| Succeeded by | ST SEV 358-88 (ISO-IR-153) |
| Other related encoding(s) | INIS Cyrillic |
This standard has become the base for the later Internet standards such as KOI8-R, KOI8-U, KOI8-RU and all the other derivatives.
Unicode is preferred to KOI-8 and its variants or other Cyrillic encodings in modern applications, especially on the Internet, making UTF-8 the dominant encoding for web pages. (For further discussion of Unicode's complete coverage, of 436 Cyrillic letters/code points, including for Old Cyrillic, and how single-byte character encodings, such as Windows-1251 and KOI8 variants, cannot provide this, see Cyrillic script in Unicode.)