O with diaeresis (Cyrillic)

O with diaeresis (Ӧ ӧ; italics: Ӧ ӧ ) is a letter of the Cyrillic script. In all its forms it looks exactly like the Ö|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.

Usage
In Altai, Khakas and Shor, it represents the close-mid front rounded vowel, like the pronunciation of the $⟨ir⟩$ in "bird" in non-rhotic dialects of English.

In Khanty, it also represents the close-mid front rounded vowel.

In Komi, it represents the schwa, like the $⟨a⟩$ in "allow".

In Kurdish, it represents the near-close near-back rounded vowel, like the $⟨oo⟩$ in "book".

In Mari, it represents the open-mid front rounded vowel, similar to.

In Udmurt, it represents the open-mid back unrounded vowel, 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").

In Tatar, this letter appeared in the 1861 Cyrillic orthography by Nikolay Ilminsky. This letter was replaced by Ө in 1939.