They retain their enlisted pay. Enlisted Marines participate in ROTC through the Marine Enlisted Commissioning Education Program (MECEP) and are referred to by their rank or by the name of the program, "MECEP." (pronounced mee-sep) MECEP Marines do not have their school paid for by the Marine Corps and generally use the Montgomery GI Bill or the Post-9/11 GI Bill to pay for school. They continue to receive pay in accordance with their rank, however any promotions while they are attending school are considered non-competitive and will be revoked if they fail out of the commissioning program. Most college NROTC units are only a part-time commitment during a student's course of study at a university or college. There are three basic parts to a student's ROTC commitment in a typical week:  One or in some cases two days a week are set aside as uniform days, where the midshipmen spend several hours attending military training such as inspections, close-order drill practices, and training lectures (either by officers attached to the NROTC unit or guest lecturers). The training is usually in the late afternoon after most classes have ended for the day, or in early mornings before classes. It is common for Marine Option midshipmen and MECEPs to have an additional training period for Marine-specific training. Usually one to three physical training sessions are required in a week (depending on the specific NROTC unit), generally early in the morning. It is common for Marine Option midshipmen and MECEPs to have additional physical training days. In addition to those activities, there are regularly scheduled classes in Naval Science that must be taken on top of the usual college load. The classes are in Naval history, Naval engineering and weapons, leadership and ethics, and other areas. Besides Naval Science classes, the Navy requires its Midshipmen to complete 2 semesters of calculus, 2 semesters of calculus-based physics, one semester diverse cultures, one year of English grammar and composition, and either National Security Policy or American Military Affairs. The Marine Corps only requires National Security Policy/American Military Affairs classes for its midshipmen. There are other miscellaneous activities scheduled occasionally; some are voluntary and some are mandatory. There are a few ROTC programs that do not follow this model, and instead require a full-time commitment from midshipmen during the school year. At a Senior Military College, the midshipmen are normally housed together with other ROTC cadets in barracks-like dormitories, a uniform is worn at least 5 days a week, and regular morning and evening formations are mandatory.