Well it’s a temporary move till my house sells and we buy another place.ATF has been ordered by Congress to keep an accurate record of NFA registered firearms. This information should include where they're presently located and their physical description --to include caliber, barrel length, and overall length.
If any of these things change (permanently), ATF wants to be notified.
I have done this with just a simple letter, less than 50 words long, telling them that I changed my address and took all my NFA toys with me to my new house in the same state.