ISO-IR-111[1] or KOI8-E[2] is an 8-bit character set. 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.
It was defined by the first (1986) edition of ECMA-113,[3] which is the Ecma International standard corresponding to ISO/IEC 8859-5, and as such also corresponds to a 1987 draft version of ISO-8859-5.[4] The published editions of ISO/IEC 8859-5 instead correspond to subsequent editions of ECMA-113, which defines a different encoding.[5]
ISO-IR-111, the 1985 edition of ECMA-113 (also called "ECMA-Cyrillic" or "KOI8-E"), was based on the 1974 edition of GOST 19768 (i.e. KOI-8). In 1987 ECMA-113 was redesigned.[5] These newer editions of ECMA-113 are equivalent to ISO-8859-5,[5][6] and do not follow the KOI layout. 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, RFC1345 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.[7][6] Due to concerns that existing implementations might use the RFC 1345 definition for those two labels, it was proposed that the IANA additionally recognise KOI8-E as a label for ECMA-113:1985 content,[7] and the IANA presently lists that label as an alias.[2]
Character set
The following table shows the ISO-IR-111 encoding. Each character is shown with its equivalent Unicode code point.
RFC1345 erroneously lists a different code page under the name ISO-IR-111, encoding the same Cyrillic characters but with a different layout. It resembles a mixture of Windows-1251 and ISO-8859-5.[7] Specifically, line A_ corresponds to ISO-8859-5, lines C_ through F_ correspond to Windows-1251[6] (equivalent to lines B_ through E_ of ISO-8859-5), and line B_ nearly corresponds to line F_ of ISO-8859-5, with the exception of the § being replaced with a ¤.
Certain codes resemble ISO-IR-111 with flipped letter case, which may have contributed to the confusion. The majority differ and are shown below.
Code page erroneously labelled "ISO-IR-111" or "ECMA-Cyrillic" in RFC1345