An extruded rail for mounting objects along the length of the rail that include an enclosed receiving and containment cavity. The extruded rail includes a receiving and containment cavity that extends from an inner surface of the rail. The receiving and containment cavity includes upper and lower walls and a back wall that define an enclosed containment area. An alignment notch is formed in the generally planar outer surface of the side rail and aligned with the receiving and containment cavity. When an object is to be attached to the rail, an opening is formed in the side rail at the alignment notch. As material is removed from the side rail during formation of the opening, the received material is entrapped within the receiving and containment cavity. Thus, the extruded rail of the disclosure receives and contains material removed during attachment of an object to the rail.