Cyrillic Small Letter U with Diaeresis

Cyrillic Small Letter U with Diaeresis at U+04F1 is a lowercase Cyrillic letter used for a distinct vowel sound in several non-Slavic languages written with Cyrillic. It belongs to the Cyrillic block and is based on the ordinary Cyrillic small u with a diaeresis to mark a different pronunciation. Its most visible use is in Mari, especially Hill Mari and Meadow Mari orthographies, where ӱ represents a front rounded vowel similar to German ü or French u. It appears in ordinary words, names, school materials, dictionaries, and local publications, not just in scholarly transcription. The letter is also used in some Cyrillic-based orthographies of Turkic and Uralic languages to separate this sound from plain у. In language documentation, census names, place names, and digital text corpora, preserving ӱ matters because replacing it with у can change pronunciation and may merge different words. Because it closely resembles Latin ü and Cyrillic у with added dots, it can be easy to confuse across scripts in mixed-language text. Searching or sorting language data may require treating it as its own Cyrillic letter rather than as a decorated form of у.