Chosen because its morse code sequence (· · · — — — · · ·) was easy to remember and recognize even through interference. Many mnemonics and backronyms were later formed from the sequence.
The code SOS is normally only used in text transmission; for voice communication, mayday is used. The sequence is normally transmitted run together without any letter spacing in between, so it is technically a single unique code rather than a series of three letters.
From the letters represented by the signal, chosen as a sequence that is easy to recall and transmit (· · · — — — · · ·); it is not, as is commonly believed, an abbreviation for "save our souls", "save our ship" or any other phrase.
SOS (plural SOS's)
- The conventional Morse code call made by a ship in distress.
- The keel has been scuppered — send out an SOS.
SOS (plural SOSes)
- (games) a children's game involving placing S's and O's on a grid, and collecting points by creating an "SOS" sequence, played with alternating turns by opponents.