The Signs, Signals, and Codes Merit Badge has us signaling using semaphore. Semaphore is communication with 2 flags. The flags themselves are 18 inches square, divided diagonally into two parts, on of red and the other white; the staffs are 24 inches long. The farthest you may be able to communicate using semaphore is about a mile or shorter, depending on light and weather conditions. The use of this form of communication is not very common anymore with the technology we have now. Still, its a fun way to communicate and learn new scouting skills. Each flag positioning refers to a different letter, number, or command. See the below chart.
Req. 4a has us spelling our first name.