In American Morse code, commonly used by U.S. coastal ships at the time this article appeared, three-dashes stood for the numeral "5", unlike Continental Morse, where three dashes stood for the letter "O". Thus, the international distress signal, known as "SOS" by most of the world, was referred to as "S5S" by many U.S. radiotelegraph operators, although the dots-and-dashes sent were the same. (Contrary to what this article states, "CQD" did not really stand for "Come Quick-Danger"; that phrase was just one which helped remember the proper order of the letters of the Marconi distress signal.)
Popular Mechanics, February, 1910, page 156:


    "S 5 S" was the message of distress which flashed through the air over Lake Michigan from the steamer "Puritan," struggling in a heavy sea, with her rudder gone.
    This message is fraught with the same significance as the now famous "C Q D" which Jack Binns sent out to call aid to the steamship "Republic," yet, not until the former sprang into prominence in connection with the "Puritan" wreck did the public know of its existence.
    "S 5 S" is the American code signal of distress. "C Q D" is the Marconi code call for help. They are used by the rival wireless companies. The combination of the letters in the American code call has no special significance, being merely a succession of dots and dashes quickly made and easily recognized, three dots, three dashes, and then three more dots, thus:  · · · - - - · · ·
    The "C Q D" call was made up of the first letters of the words "Come--Quick--Danger."
    The existence of the two rival companies having different codes was charged by an operator at Detroit, Mich., with being responsible for the loss of 14 lives on the steamship "Clarion which was burned on Lake Michigan on December 8th. The Detroit operator declared that the operator on a steamer which was in sight of the "Clarion," and which flashed the distress signal, refused to answer and give the location of the burning steamer when he learned that an operator for the rival company was receiving the message.