High Quality Content by WIKIPEDIA articles! KOI8-R is an 8-bit character encoding, designed to cover Russian, which uses a Cyrillic alphabet. It also happens to cover Bulgarian, but is not used since CP1251 is accepted. A derivative encoding is KOI8-U, which adds Ukrainian characters. The original KOI-8 encoding was designed by Soviet authorities in 1974. KOI8 remains much more commonly used than ISO 8859-5, which never really caught on. Another common Cyrillic character encoding is Windows-1251. The usage of these older code pages is being replaced with Unicode as a more common way to represent Cyrillic together with other non-Latin languages.