Morse code was later made the standard by the International Telecommunication Union (ITU). Morse's original code specification, largely limited to use in the United States and Canada, became known as American Morse code or "railroad code". American Morse code is now seldom used except in historical re-enactments. In aviation, pilots use radio navigation aids. To ensure that the stations the pilots are using are serviceable, the stations transmit a set of identification letters (usually a two-to-five-letter version of the station name) in Morse code. Station identification letters are shown on air navigation charts. For example, the VOR-DME based at Vilo Acuña Airport
Telegraph code Telegraph code A telegraph code is one of the character encodings used to transmit information through telegraphy machines. The most famous such code is Morse code. Morse code can be transmitted and received with very simple electrical equipment, such as the electrical telegraph invented in 1816. Morse code represents each letter of the alphabet as a series of "dots and dashes" (short and long bursts of electronically-generated noise). The speed of sending is directly related to the length of the shortest (dot) element: a dash is three dots long, an inter-character gap is the same length (3 dots), and inter-word