Driving in Stillwater, I found myself behind an Oklahoma State University transit bus.
The first thing I noticed was the blue diamond symbol with "CNG" for compressed natural gas. The second thing I noticed was a sticker advertising "PickensPlan.com" accompanied by symbols representing the U.S. and abundant energy resources.
The transit bus is property of the state of Oklahoma and had a state tax-exempt license tag.
I believe it is improper and probably against state law and /or policy to promote or display advertising on state property for something that is not a function of the state of Oklahoma.