Maritime flag signalling, generally flaghoist signalling, is the principal means other than radio by which ships communicate to each other or to shore; distinguished from flags showing nationality, ownership, or (for naval vessels) organizational status. Virtually all signalling by non-naval vessels (whether by flaghoist, semaphore, signal lamp, or other means) is now organized under the International Code of Signals, which specifies a standard set of flags and codes; naval vessels generally use an extended set of flags and their own codes. This article will touch on the historical development of maritime flag signalling.