O with macron
|The Cyrillic script|
O with macron also appears in the Transcarpathian dialect of Carpatho-Rusyn, the only Slavic language to do so. In Carpatho-Rusyn, o with macron is pronounced like /o:/ being shifted towards /u/ at different grades. Although the use of this letter is not mandatory and it usually substituted with the Cyrillic letters O or I.