((a)) Original appointments as regular officers of the Navy in a grade below lieutenant commander in the line and in staff corps established by the Secretary of the Navy under and designated by the Secretary for the purposes of this section may be made from—
((1)) warrant officers;
((2)) chief petty officers; and
((3)) first-class petty officers;
((b)) Original appointments as regular officers of the Marine Corps in a grade below major may be made from—
((1)) warrant officers;
((2)) master sergeants; and
((3)) technical sergeants;
((c))
((1)) 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.
((2)) This subsection applies to an officer of the Navy and Marine Corps who—
((A)) is on the active-duty list;
((B)) holds a permanent enlisted or warrant officer grade;
((C)) is designated for limited duty under subsection (a) of ; and
((D)) 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 .
((d)) To be eligible for an appointment under this section a member must have the qualifications specified in and have completed at least 8 years of active naval service, excluding active duty for training in a reserve component.
((e)) 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.
((f)) Any officer designated for limited duty, upon his application and upon determination by the Secretary of the Navy that he is qualified, may—
((1)) 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;
((2)) if he is in a staff corps of the Navy, be assigned to unrestricted performance of duty in that corps; or
((3)) if he is in the Marine Corps, be assigned to unrestricted performance of duty.
((g)) The Secretary shall prescribe regulations for the appointment, designation, and assignment of officers under this section.