Military Registrations...
The smog stuff must have been intact. Mine isn't - in fact I'm going to convert the F100 to a diesel someday and use the 302 for a race buggy.
What bugs me the most is that I clearly recall a message about local inspections. It stated that if you are from an area where equivalent inspections are not required you are EXEMPT from local inspections if your vehicle is registered in your home state.
There are five copies of that message at home, I wish I had one of them here...
I used it on the base cops in Norfolk Virginia - it was strange to hear them say: "OOPS! Sorry sir..."