S.C. Code § 56-5-4600
Reflectors, when required pursuant to Section 56-5-4580, shall be mounted at a height not less than twenty-four inches and not higher than sixty inches above the ground on which the vehicle stands, except that if the highest part of the permanent structure of the vehicle is less than twenty-four inches the reflector at such point shall be mounted as high as that part of the permanent structure will permit. The rear reflectors on a pole trailer may be mounted on each side of the bolster or load. Any required red reflector on the rear of a vehicle may be incorporated with the tail lamp, but such reflector shall meet all the other reflector requirements of this chapter.
Clearance lamps shall be mounted on the permanent structure of the vehicle in such manner as to indicate its extreme width and as near the top thereof as practicable. Clearance lamps and side-marker lamps may be mounted in combination, provided illumination is given as required herein with reference to both.
S.C. Code § 56-5-4600