Hi Steve. Anyone could simply match up callsign digits against the state abbreviation in each licensee's address, but here's the sticky part: The FCC says only that you must be able to receive mail at the address on file and reply ibn a reasonable time period (usually either 15 or 30 days, depending on the need for your reply). It doesn't have to be the location of your transmitting station equipment. That interpretation supposedly saved the FCC huge amounts of time to process all the address change modifications. I think John Johnston could offer some salty comments about the wisdom of that policy change.