Alternative names for RBs are "deep backs" and "setbacks", although the latter is disfavored because it has also been used for backs in general, both on offense and defense. There is, moreover, a generic term for the deeper-playing backs (CB & S) on defense: "defensive back" (DB), appropriately enough. The term excludes the linebackers, even though they be backs in the traditional sense because they are usually not on their team's line of scrimmage. There also exist the generic terms "defensive lineman" (DL) and "offensive lineman" (OL), although the latter refers only to the interior linemen, excluding the ends because of their eligibility to receive forward passes.