By virtue of and pursuant to the authority vested in me by Title I of the Selective Service Act of 1948 (62 Stat. 604), and as President of the United States, the following definitions are hereby prescribed for the purposes of section 6(j) of the said Act:
1. The term "noncombatant service" shall mean (a) service in any unit of the armed forces which is unarmed at all times; (b) service in the medical department of any of the armed forces, wherever performed; or (c) any other assignment the primary function of which does not require the use of arms in combat; provided that such other assignment is acceptable to the individual concerned and does not require him to bear arms or to be trained in their use.
2. The term "noncombatant training" shall mean any training which is not concerned with the study, use, or handling of arms or weapons.
HARRY S. TRUMAN
THE WHITE HOUSE,
January 13, 1949
Harry S Truman, Executive Order 10028—Defining Noncombatant Service and Noncombatant Training Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/231114