Section 41
SEC. 41. Noncommissioned officers of the Regular Force regular force between the ages of twenty-one and thirty years who are recommended for appointment as third lieutenants shall pursue the course of instruction of six months prescribed for those who have completed their trainee instruction, and who are recommended for training to qualify as reserve officers. Upon satisfactory completion of this course they may be appointed and commissioned third lieutenants of the Reserves and assigned to an organization of the Reserve Force. Except upon mobilization, no service as a reserve officer may be performed by an enlisted man of the Regular Force.