22 U.S.C. § 4005

(a) Recommendations for promotion made by selection boards shall be submitted to the Secretary in rank order by salary class or in rank order by specialization within a salary class. The Secretary shall make promotions and, with respect to career appointments into or within the Senior Foreign Service, shall make recommendations to the President for promotions, in accordance with the rankings of the selection boards. (b) Notwithstanding subsection (a), in special circumstances set forth by regulation, the Secretary may remove the name of an individual from the rank order list submitted by a selection board or delay the promotion of an individual named in such a list.