I think I've camped out of just about every kind of shelter and also sans shelter and I never leave a trace. When I was a boy, my uncle had a camp trailer with all the comforts. My Dad, my Uncle and I camped in it for a week. Before we left (self contained or not) we policed the area and made certain nothing was left behind. We even dug out the ashes from our campfire, scattered them and raked the spot where the fire was. The only thing we left behind were tire tracks and the first rain took care of those. This is how I was taught to camp and it never left me.