No rust just what does it mean

If I see an ad that says no rust to me it means run like hell in the other direction!

That funny you say that, because I could swear the people who are upfront and almost apologetic about selling their "rusty" cars (where the cars are mint with just minor surface rust).......are in direct opposites to these other guys who are loudly proclaiming their mint, garaged grandma "barn finds".....that usually have cardboard and birthday cake bondo frosting in the quarter panels. That's a trip!