O with diaeresis (Cyrillic)

O with diaeresis is a letter of the Cyrillic script.
In all its forms it looks exactly like the Latin letter 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, Khanty and Shor, it represents the close-mid [front rounded vowel], like the pronunciation of the in "bird" in non-rhotic dialects of English.
In Komi, it represents the schwa, like the in "allow".
In Kurdish, it represents the near-close near-back rounded vowel, like the 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 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.
In Tatar, this letter appeared in the 1861 Cyrillic orthography by Nikolay Ilminsky. This letter was replaced by Ө in 1939.
O with diaeresis and macron is a letter from the Cyrillic script. It is used in the southern dialects of the Selkup language, to indicate a long Ӧ.