D.C. Code § 49-310
The Commanding General is authorized to prescribe a system of examination of enlisted men to determine their fitness for promotion to the grade of 2nd lieutenant.
Mar. 1, 1889, 25 Stat. 775, ch. 328
as added Feb. 18, 1909, 35 Stat. 630, ch. 146, § 18
1973 Ed., § 39-211.
1981 Ed., § 39-310.