KOI8-R (RFC 1489) is an 8-bitcharacter encoding derived from theKOI-8 encoding by the programmerAndrei Chernov in 1993 and designed to coverRussian, which uses theRussian subset of aCyrillic script. KOI-8, on its turn, is an 8-bit extension of theKOI-7 encoding, which inherited aphonetic correspondence of Russian and Latin letters from theMTK-2teletype code. As a result, Russian Cyrillic letters in KOI8-R are in pseudo-Latin alphabetical order rather than the normal Cyrillic one like inISO 8859-5. Although this may seem unnatural, this has the useful effect that if the 8th bit is stripped, the text remains partially readable in anyASCII-based encoding (including KOI8-R itself) as a case-reversedtransliteration. For example, "Код для обмена и обработки информации" (the Russian meaning of the "KOI" acronym) becomeskOD DLQ OBMENA I OBRABOTKI INFORMACII.

KOI-8 stands for8-bitnyy kod dlya obmena i obrabotki informatsii (Russian:8-битный код для обмена и обработки информации) which means "8-Bit Code for Information Interchange".^[1] InMicrosoft Windows, KOI8-R is assigned the code page number 20866. InIBM, KOI8-R is assigned code page 878.^[2][3] KOI8-R also happens to coverBulgarian.

It lacks proper quotation marks for these languages: both «...» and the Bulgarian „...“.Windows-1251 does support these, as well as more letters, and has thus become more popular. KOI8-R is used by less than 0.004% of websites, mostly Russian and Bulgarian.^{[citation needed]}Unicode andUTF-8 is preferred to single-byte Cyrillic encodings in modern applications, Unicode contains 436Cyrillic letters including forOld Cyrillic.

The following table shows the KOI8-R encoding. Each character is shown with its equivalentUnicode code point.

• KOI8-B, a derivation of KOI8-R with only the letter subset implemented
• KOI8-U, another derivative encoding which addsUkrainian characters
• KOI character encodings
• RELCOM
• Windows-1251, another common Cyrillic character encoding

• Flohr, Guido; Kiss, Gabor; Chernov, Andrey A. (2016) [2006]."Locale::RecodeData::KOI8_R - Conversion routines for KOI8-R".CPAN libintl-perl. 1.0.Archived from the original on 2017-01-15. Retrieved2017-01-15.
• Kostis, Kosta."koi8-r (Russian U*IX encoding, also used by RELCOM)". 1.20.Archived from the original on 2017-01-16. Retrieved2017-01-16.
• RFC 1489
• "KOI8-R (RFC 1489)".Kermit.Columbia University. Retrieved2020-06-24.
• Kornai, Andras; Birnbaum, David J.; da Cruz, Frank; Davis, Bur; Fowler, George; Paine, Richard B.; Paperno, Slava; Simonsen, Keld J.; Thobe, Glenn E.; Vulis, Dimitri; van Wingen, Johan W. (1993-03-13)."CYRILLIC ENCODING FAQ Version 1.3". 1.3. Retrieved2020-06-24.

• Universal Cyrillic decoder, an online program that may help recoveringCyrillic texts with broken KOI8-R or othercharacter encodings.
• "The Home of the KOI8-R since 1995". 1995. Retrieved2016-12-05.
• Czyborra, Roman (1998-11-30) [1998-05-25]."The Cyrillic Charset Soup".Archived from the original on 2016-12-03. Retrieved2016-12-03.
• Hohlov, Yu. E."Cyrillic Information Representation in Electronic Form - Character Set (Code Page) Tables".Archived from the original on 2016-12-05. Retrieved2016-12-05.
• Nechayev, Valentin (2013) [2001]."Review of 8-bit Cyrillic encodings universe".Archived from the original on 2016-12-05. Retrieved2016-12-05.

• Character sets
• Computing in the Soviet Union

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