Wis. Stat. § 341.142
If any person who is registering or has registered a vehicle specified in s. 341.14(6r) (b) 1 submits a statement from the U.S. department of veterans affairs certifying to the department that the person has been awarded a medal authorized under an act of congress relating to that person's service in the U.S. armed forces, as defined in s. 40.02(57m) , the department shall, free of charge, procure, issue and deliver to that veteran one decal, similar in appearance to the medal awarded to that veteran, for each motor vehicle registered in the name of that veteran. Notwithstanding s. 341.61(3) , a decal issued under this section shall be displayed in the manner directed by the department on the rear registration plate of the vehicle registered in the name of the veteran to whom the decal was issued. The department shall specify one combination of colors and design for each medal authorized under an act of congress for which a statement has been received by the department under this section, except that the department may not specify the colors or design unless the colors and design are approved in writing by the state department of veterans affairs. Not more than one decal may be issued under this section for each motor vehicle registered in the name of a veteran.
Wis. Stat. § 341.142