O with diaeresis (Ӧ ӧ; italics:
Ӧ ӧ) is a letter of the Cyrillic script. In all its forms it looks exactly like the Latin letter Ö (Ö ö Ö ö).O with diaeresis is used in the alphabets of the Altai, Khanty, Khakas, Komi, Kurdish, Mari, Shor and Udmurt languages.
In Altai, Khakas, Khanty and Shor, it represents the close-mid front rounded vowel pronounced as //ø//, like the pronunciation of the (ir) in "bird" in non-rhotic dialects of English.
In Komi, it represents the schwa pronounced as //ə//, like the (a) in "allow".
In Kurdish, it represents the near-close near-back rounded vowel pronounced as //ʊ//, like the (oo) in "book".
In Mari, it represents the open-mid front rounded vowel pronounced as //œ//, similar to pronounced as //ø//.
In Udmurt, it represents the open-mid back unrounded vowel pronounced as //ʌ//, like the (u) in "up".
In Russian books until the beginning of the 20th century, the letter Ӧ has been sporadically used instead of Ё in foreign names and loanwords (for example, the city of Cologne, Germany, which is Köln in German, might have been rendered in Russian as "Кӧльн").[1]
In Tatar, this letter appeared in the 1861 Cyrillic orthography by Nikolay Ilminsky. This letter was replaced by Ө in 1939.