Binding case - Canadian Active Service Force (CASF) "S - Y", 1939 In 1939, the Canadian Active Service Force (CASF) was mobilized; similar to the CEF, this was a mobilization of prewar Permanent Force (PF) and Non-Permanent Active Militia (NPAM) units, who retained their traditional titles. In 1940, the land forces of Canada were retitled. The CASF became the Canadian Army (Overseas), the Permanent Force became the Canadian Army (Active) and the NPAM became the Canadian Army (Reserve).