Koppa or
Qoppa (; as a modern numeral sign: ) is a letter that was used in early forms of the
Greek alphabet, derived from
Phoenician qoph . It was originally used to denote the /k/ sound, but dropped out of use as an alphabetic character in favor of
Kappa (Κ). It has remained in use as a numeral symbol (90) in the system of
Greek numerals, although with a modified shape. Koppa is the source of
Latin Q, as well as the
Cyrillic numeral sign of the same name (
Koppa).