Original: 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.
Simplified: It was introduced by the German government in radio regulations on April 1, 1905. It became the worldwide standard when it was included in the second International Radiotelegraphic Convention, which was signed on November 3, 1906. This convention developed many Service Regulations to be added to the main agreement, which was signed on November 3, 1906, and became effective on July 1, 1908.