Another thought, I had filled out the registration for my 152 and then decided to add my wife as co-owner .. the only room on the form was above my name, so I wrote her name in there. Well, the FAA treats the first name as the primary owner, or at least they only use the first name on correspondence, so everything from the FAA and the resulting junk mail always came to my wife as the airplane owner! She wasn't amused.
Terry
