Video encyclopedia

03/11/1906 Morse code distress signal "SOS" becomes worldwide standard

SOS is the International Morse code distress signal the overscore indicates that the normal gaps between the letters should be omitted. It became the worldwide standard under the second International Radiotelegraphic Convention.


  • Essentials 

  • SOS 

  • Formalization 

  • Later developments 

  • Historical SOS calls