JIUKEN

JIUKEN (ЙІУКЕН, also known as YIUKEN and YYUKEN) is an old Russian language keyboard layout for typewriters. JIUKEN was replaced by JCUKEN, because of the Russian alphabet reform in 1917, which made the letters Ѣ, І, Ѵ, and Ѳ obsolete, and the letter Ъ decreased in usage significantly.