No rust just what does it mean

No rust,just what does it mean? I see adds were the seller says no rust,but every time I have look at a car I find rust, floor,trunk,rails,cross member it goes on,now some is some what bad,and no so bad, down to what hell does he thinking what he has.Pleas explain,:wack:

My rule is: surface rust isn't "rust"......pinholes or bubbling paint areas that I could jab a screwdriver right through....IS "rust". The middle ground where surface rust has caused the metal to become rough and scarred (like suspension components/crossmembers of "back east" cars) is cause for points subtracted.

Sometimes, when I go look at a car for sale, and the seller's ad says "some rust" and I go out and it's just minor surface rust.......I just smile inside.