Koppa

Koppa or Qoppa (uppercase: Ϙ, lowercase: ϙ, numeral: ϟ) is a letter that was used in early forms of the Greek alphabet, derived from Phoenician qoph (𐤒). It was originally used to denote the /k/ sound, but dropped out of use as an alphabetic character and replaced by 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).