RRRR may refer to: * the reporting mark for the

Rock and Rail LLC Rock and Rail is a short line railroad operating in southern Colorado that is currently a subsidiary of Martin Marietta Materials Martin Marietta Materials, Inc. is an American company and a member of the S&P 500 Index. The company is a sup ...

Raritan River Railroad The Raritan River Rail Road was a shortline railroad in Middlesex County, New Jersey U.S., Founded in 1888, it was based in South Amboy, from which it ran west as far as New Brunswick. It served both passengers and freight in its heyday and op ...

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morse code Morse code is a method used in telecommunication to encode text characters as standardized sequences of two different signal durations, called ''dots'' and ''dashes'', or ''dits'' and ''dahs''. Morse code is named after Samuel Morse, one of ...

for surface raider, used in conjunction with

SOS is a Morse code distress signal (), used internationally, that was originally established for maritime use. In formal notation is written with an overscore line, to indicate that the Morse code equivalents for the individual letters of "SOS" ...

See also