In a suit against a subordinate officer, the head of a department or other superior officer is an indispensable party if the relief sought would require the superior officer to take action, either directly or through a subordinate. See Williams v. Fanning, 332 U.S. 490, 493 (1947); Hynes v. Grimes Packing Co., 337 U.S. 86, 96 (1949). See also 5 U.S.C. § 702.
[cited in USAM 4-2.150]