10 U.S.C. § 8139: Regular Navy and Regular Marine Corps: officers designated for limited duty

warrant officers; chief petty officers; and first-class petty officers; warrant officers; master sergeants; and technical sergeants; An officer described in paragraph (2) may be given an original appointment as a regular officer of the Navy or the Marine Corps, as the case may be, in the grade, and with the date of rank in that grade, in which the officer is serving on the day before such original appointment. is on the active-duty list; holds a permanent enlisted or warrant officer grade; is designated for limited duty under subsection (a) of section 8146 of this title ; and is serving in the grade of lieutenant commander or commander, or in the grade of major or lieutenant colonel, under a temporary appointment under subsection (d) of section 8146 of this title . To be eligible for an appointment under this section a member must have the qualifications specified in section 532(a) of this title and have completed at least 8 years of active naval service, excluding active duty for training in a reserve component. Each officer appointed under this section is known as an officer designated for limited duty. He may not suffer any reduction in the pay and allowances to which he was entitled at the time of his appointment because of his former permanent status. if he is in the line of the Navy, be designated for engineering duty, aeronautical engineering duty, or special duty, or be assigned to unrestricted performance of duty; if he is in a staff corps of the Navy, be assigned to unrestricted performance of duty in that corps; or if he is in the Marine Corps, be assigned to unrestricted performance of duty. The Secretary shall prescribe regulations for the appointment, designation, and assignment of officers under this section.