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SOS

SOS is the International Morse code distress signal (▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄); the overscore indicates that the normal gaps between the letters should be omitted. It is used as a start-of-message mark for transmissions requesting help when loss of life or catastrophic loss of property is imminent. Other prefixes are assigned for mechanical breakdowns, requests for medical assistance, and a relayed distress signal originally sent by another station. This distress signal was first adopted by the German government radio regulations effective 1 April 1905, and became the worldwide standard under the second International Radiotelegraphic Convention, which was signed on 3 November 1906, and became effective on 1 July 1908. SOS remained the maritime radio distres… more »