((a)) The Secretary may pursuant to a recommendation of the Foreign Service Grievance Board, an equal employment opportunity appeals examiner, or the Special Counsel of the Merit Systems Protection Board, and shall pursuant to a decision or order of the Merit Systems Protection Board—
((1)) recommend to the President a promotion of a member of the Service under ;
((2)) promote a member of the Service under ;
((3)) grant performance pay to a member of the Senior Foreign Service under ; or
((4)) grant a within-class salary increase under to a member of the Service who is assigned to a salary class in the Foreign Service Schedule.
((b)) In implementing subsection (a) of this section and in cases in which the Secretary has exercised the authority of , the Secretary may, in special circumstances set forth by regulation, make retroactive promotions, grant performance pay, make retroactive within-class salary increases, and recommend retroactive promotions by the President.