swallowtail

In flag terminology, a swallowtail is either a V-shaped cut in a flag that causes the flag to end in two points at the fly; or any flag that has this V-shaped cut. The name comes from the forked tail that is a common feature of the swallow species of birds. Variants Double-pointed Common in the Nordic countries, this swallowtail flag contains a vertical section in the centre of the fly.