SOS

SOS is the international Morse code distress signal (· · · – – – · · ·). This distress signal was first adopted by the German government in radio regulations effective April 1, 1905, and became the worldwide standard under the second International Radiotelegraphic Convention, which was signed on November 3, 1906, and became effective on July 1, 1908. SOS remained the maritime radio distress signal until 1999, when it was replaced by the Global Maritime Distress and Safety System. SOS is still recognized as a visual distress signal.