A butterfly collar (or wing collar) is a stiff, short, stand-up shirt collar with points that fold down horizontally at the front, resembling butterfly wings, designed to be worn under tuxedos or formalwear with a bow tie, with the points often tucked behind the tie for a sleek, formal look. Key details include its small size, stiffness (often achieved with starch or plastic inserts), and specific pairing with bow ties for formal occasions.