Cap Badge - Canadian Signal Corps The signal service acted as a component of the Canadian Engineers during the First World War, providing signal companies for the four divisions, two artillery signal units, and a corps signal company for the Canadian Corps. A signal company also served with the Canadian contingent in Siberia in 1919. On 31 March 1929, The Corps of Guides was absorbed by the corps. The First World War saw the development of spark wireless, buried telephone cable and message rockets, in addition to motorcyclist dispatch riders, messenger dogs, carrier pigeons, and the old reliable lamp and flags.