Does that mean they were used? Or refurbished?
Neither, they have slight blemishes that didn't allow them to pass inspection and be sold as regular "firsts". Many times the blemish or imperfection is very slight and doesn't detract at all from the shoe but YMMV. If you order one from one of the stores they will usually be willing to email you pictures of the shoes before you buy them. The warehouse can't do that.