Iowa Code § 29A.78: Brevet rank.

The commander in chief, on the recommendation of the adjutant general, may commission by brevet general and field grade officers in the national guard whose names appear on the roll of retired military personnel as defined in section 29A.23 in the next higher grade than that held at retirement or resignation. Brevet rank is only honorary and does not confer any privilege, precedence or command or pay any emoluments. Brevet officers may wear the uniform of their brevet rank on occasions of ceremonies related to state functions only.