The Royal Canadian Air Force Police was responsible for military police functions for the Royal Canadian Air Force (RCAF). In 1940 the RCAF set up the Guards and Discipline Branch, which later changed its name to the Directorate of Provost and Security Services (DPSS). The DPSS provided police mainly for guard, security, and disciplinary duties. During the Second World War and into the post-war period, the RCAF Police were known as the RCAF Service Police (RCAF SP) and police personnel were referred to as "SPs".