Enlistment bars, denoting each honorable enlistment completed, were pinned on the ribbon as attachments. It is thus, very important to understand factors that motivate enlistment and reenlistment. Immunizations are compulsory for military enlistment in the U.S. He joined the Marine Corps on April 15 for his mandatory military enlistment. This lasted until October 1943 when voluntary enlistment in the Seabees ceased until December 1944. Immunizations are often compulsory for military enlistment in the U.S. The first volunteers were skilled recruits at enlistment. Plans for a doctoral degree were delayed to accommodate his military enlistment. Recruitment was intended to be by voluntary enlistment. Service is voluntary and the minimum age for enlistment is 18 years. Enlistment in all official Australian contingents totalled 16,463. They were charged with obstructing the recruitment and enlistment service, and convicted. On July 10, 2018 Ryeowook completed his mandatory enlistment. Bloch kept a war diary from his enlistment. At the camps, prisoners were sorted based on their unit and year of enlistment.