The control flag marks the feature that is circled on the map. It is made of fabric hung on a triangular kite-like wire frame. Each of the three square cloth faces is made up of a white upper triangle and an orange or red lower triangle. The flag is usually hung from a branch or a cane near the control site.Each flag is assigned a unique control code, usually an number in the range 201-240 for our Summer League events. These codes are listed in the description sheets that define the controls for each course and allow the orienteer to determine if the control is in fact the correct one. Attached to or near the control flag is an SI (SportIdent) Unit with the "control code". When an orienteer reaches the correct control, he/she dips their SI card into the SI unit until they hear an audible "beep" - this means that their presence at the control has been recorded on to their SI card.