U+0480 "Ҁ" Cyrillic Capital Letter Koppa Unicode Character

U+0480 "Ҁ" Cyrillic Capital Letter Koppa is a historical letter from the early Cyrillic alphabet, derived from the Greek letter koppa (Ϙ), and was used primarily as a numeric sign to represent the number 90 in Old Church Slavonic texts rather than as a phoneme for a distinct sound. Its shape resembles a circle with a cross or a vertical line extending downward, and it is one of several archaic Cyrillic letters that were dropped from the alphabet during the standardization reforms of the 18th century, such as those by Peter the Great and later the 1918 orthographic reform. Today, it survives only in specialized liturgical, historical, or paleographic contexts, where it may appear in editions of ancient manuscripts or in scholarly works on Slavic philology.