What is the difference between a backyard barn and a private stable?
A backyard barn is similar to a mini barn. When you are a backyard barn owner, you must list yourself as backyard barn @ boarding barn. While you are a backyard barn, you are still technically boarding with your mentor, but you have more prestige in the game (and more player benefits) than a boarder. A private stable owner is completely independent of their mentor and is free to list themself as such.