32 CFR §1633.1

1. (a)The Director of Selective Service may in accord with the provisions of this chapter classify a registrant into any class for which he is eligible except Classes 1-A-0, 1-0, 2-D, 3-A, and 4-D: Provided, That, the Director may not reclassify a registrant other than a volunteer for induction, into Class 1-A out of another class prior to the expiration of the registrant's entitlement to such classification. The Director may, before issuing an induction order to a registrant, appropriately classify him if the Secretary of Defense has certified him to be a member of an armed force or reserve component thereof.
2. (b)The National Selective Service Appeal Board may in accord with part 1653 of this chapter classify a registrant into any class for which he is eligible.
3. (c)A district appeal board may in accord with part 1651 of this chapter classify a registrant into any class for which he is eligible.
4. (d)A local board may in accord with part 1648 of this chapter classify a registrant into Class 1-A-0, 1-0, 2-D, 3-A, or 4-D for which he is eligible.
5. (e)A local board may also classify a registrant into Class 1-C, 1-D-D, 1-D-E, 1-O-S, 1-W, 3-A-S, 4-A, 4-A-A, 4-B, 4-C, 4-F, 4-G, 4-T or 4-W for which he is eligible upon request by the registrant for a review of a classification denial action under § 1633.1(f). No individual shall be classified into Class 4-F unless the Secretary of Defense has determined that he is unacceptable for military service.
6. (f)Compensated employees of an area office may in accord with § 1633.2 may classify a registrant into an administrative class for which he is eligible. No individual shall be classified into Class 4-F unless the Secretary of Defense has determined that he is unacceptable for military service.