https://codes.findlaw.com/il/chapter-625-vehicles/il-st-sect...
> § 3-402. Vehicles subject to registration; exceptions.
> A. Exemptions and Policy. Every motor vehicle, trailer, semitrailer and pole trailer when driven or moved upon a highway shall be subject to the registration and certificate of title provisions of this Chapter except:
> ...
> (6) Any vehicle which is owned and operated by the federal government and externally displays evidence of federal ownership. It is the policy of the State of Illinois to promote and encourage the fullest use of its highways and to enhance the flow of commerce thus contributing to the economic, agricultural, industrial and social growth and development of this State, by authorizing the Secretary of State to negotiate and enter into reciprocal or proportional agreements or arrangements with other States, or to issue declarations setting forth reciprocal exemptions, benefits and privileges with respect to vehicles operated interstate which are properly registered in this and other States, assuring nevertheless proper registration of vehicles in Illinois as may be required by this Code;
> with references.
Please provide a reference for future comments.