Vexillological symbol

Flag information symbols are used by vexillologists to indicate certain characteristics of flags, such as where they are used, who uses them, and what they look like. The symbols were created by vexillologist Whitney Smith and then adopted by the International Federation of Vexillological Associations (FIAV) in the early 1970s. Vexillologist Željko Heimer added the symbols for normal and historical in the early 1990s.