"Brevet" is a word in LAW AND LEGAL, ENGLISH

In military law. A corn-mission by which an oflicer is promoted to the next higher rank, but without confer-ring a right to a corresponding increase of pay

To confer rank upon by brevet.

A warrant from the government, granting a privilege, title,
or dignity. [French usage].

Taking or conferring rank by brevet; as, a brevet colonel;
a brevet commission.

A commission giving an officer higher rank than that for
which he receives pay; an honorary promotion of an officer.