It is a multinational extension of KOI-8 for Belarusian, Macedonian, Serbian, and Ukrainian (except Ґґ which is added to KOI8-F).
The name "ISO-IR-111" refers to its registration number in the ISO-IR registry, and denotes it as a set usable with ISO/IEC 2022.
This confusion has led to a common misconception that ISO-8859-5 was defined in or based on GOST 19768-74.
[6] Possibly as another consequence of this, RFC 1345 erroneously lists a different codepage under the names "ISO-IR-111" and "ECMA-Cyrillic", resembling ISO-8859-5 with re-ordered rows, and partially compatible with Windows-1251.
A modified version named KOI8 Unified or KOI8-F was used in software produced by Fingertip Software, adding the Ґ in its KOI8-U location (replacing the soft hyphen and displacing the universal currency sign), and adding some graphical characters in the C1 control codes area, mainly from KOI8-R and Windows-1251.