officer restricted in the performance of duty
(8)The term “officer restricted in the performance of duty” means an officer of the Navy designated for engineering duty, aeronautical engineering duty, special duty, or limited duty, or an officer of the Marine Corps designated for limited duty. (b)For the purposes of this subtitle, a member of the naval service who holds a temporary appointment in a grade higher than his permanent grade is considered, unless otherwise specified, to be serving in the higher grade.