KOI-7 N1 (
КОИ-7 Н1) was first standardized in GOST 13052-67, and later also in
ISO 5427. It is sometimes referred to as "koi-0" as well. Compared to
ASCII and
ISO 646 uppercase and lowercase letters are swapped in order to make it easier to recognize Russian text when presented using ASCII. To trim the alphabet into chunks of 32 characters the dotted
Ё/ë was dropped. In order to avoid conflicts with ASCII's and ISO 646's definition as
DEL and its usage as
EOF marker (-1) in some systems, it dropped the "CAPITAL HARD SIGN"
Ъ that would have naturally resided at this location. In a Bulgarian variant the unnecessary Russian "CAPITAL YERY"
Ы at code point 121 was replaced by the "CAPITAL HARD SIGN" Ъ. ==KOI-7 N2==