Per I-CAR curriculum: “Many parts of a vehicle are not one piece, but composed of multiple pieces that are joined together. Replacing a portion of a part at factory seams is sometimes recommended. Sectioning does this at an area of the part away from factory seams, creating a new joint. Either of these partial replacement methods requires a recommendation from the vehicle maker, with either a procedure or available partial part. There may also be a recommendation to partially replace a part at factory seams at one location, and section in another location.”