Royal Mail Ship (sometimes
Steam-ship or
Steamer) is usually seen in its abbreviated form
RMS, a designation which dates back to 1840. It is the
ship prefix used for seagoing vessels that carry
mail under contract to the British
Royal Mail. Any vessel designated as "RMS" has the right both to fly the pennant of the Royal Mail when sailing and to include the Royal Mail "crown" logo with any identifying device and/or design for the ship.