KOI7
From Just Solve the File Format Problem
KOI7 (or KOI-7, КОИ-7, Kod Obmena Informatsiey 7 bit, GOST 13052-67) is a 7-bit encoding of the Cyrillic alphabet. Several revisions exist, including KOI7-switched, which uses the Shift In (SI) and Shift Out (SO) control characters (in the C0 controls) to switch between different character sets.