"Certa Cito" (Latin for "Swift and Sure") is the motto of the Royal Corps of Signals, the Army unit that provides telecommunications services to the British Army around the world. The badge features the Roman god Mercury, winged messenger of the gods. The caduceus is a stick entwined by two serpents; the Greek "version" of Mercury, Hermes, supposedly used his staff to separate two fighting snakes, who then wrapped themselves around the stick, balancing in harmony. (The caduceus is different to the Rod of Asclepius, the traditional symbol representing medicine, which consists of a single serpent around a stick).

The Royal Corps of Signals has been closely associated with Swanage, and particularly the railway, for 35 years. Corps members regularly come on training exercises in Purbeck, assisting the railway with a range of civil engineering and of course telecomms activities; for example erecting telegraph poles, laying cable runs etc. They have "adopted" the first station out of Swanage, Herston Halt, which they helped to build (there was no station there in BR days), and today help in its maintenance, and in that of their stores van and base which is located there. In June 2017, a visiting mainline locomotive (66756) was officially named "Royal Corps of Signals" at Swanage station. On that day, the Corps' emblems on the War Memorial were officially unveiled. Over the years, the Corps has taken part in more than 65 exercises involving over 5000 men and women. See more at the railway's website.