The name stands for Kod obmena informatsiey (Russian: Код обмена информацией) which means "Code for Information Interchange".
This is due to characters being placed in a special order (128 codepoints apart from the Latin letter they sound most similar to), which, however, does not correspond to the alphabetic order in any language that is written in Cyrillic and necessitates the use of lookup tables to perform sorting.
The first 26 characters from А (0xE1) in KOI8-R are А, Б, Ц, Д, Е, Ф, Г, Х, И, Й, К, Л, М, Н, О, П, Я, Р, С, Т, У, Ж, В, Ь, Ы, З.
The original KOI encoding (1967) was a 7-bit code page named KOI-7 (КОИ-7), which did not contain lowercase letters.
The family members are: Additionally, GOST R 34.303-92 defines "KOI-8 V1" which is ISO-IR-153, and "KOI-8 N1" and "KOI-8 N2" which are variants of Code page 866.