From parallel waves or two faced lines: Centers Cast 3/4 (Counter Fan) or Cast 1/4 (Counter Hinge) to form a temporary wave across the set and walk straight ahead, sliding together shoulder to shoulder. The ends meanwhile Counter Rotate to form Three and One Lines.
Bill Davis 1975
This definition is from The Handbook of Modern Square Dancing by Jay King.
It is provided here for informational and educational purposes only.