South Carolina Code 16-11-600. Notice of trespassing; purple paint
(B) The owner or tenant of any lands may accomplish the posting of notice as follows:
(1) by posting a notice in four conspicuous places on the borders of such land prohibiting entry thereon; or
(2) by marking boundaries with a clearly visible purple-painted marking, consisting of one vertical line not less than eight inches in length and two inches in width, and the bottom of the mark not less than three nor more than six feet from the ground or normal water surface. These marks must be affixed to immovable, permanent objects that are not more than one hundred yards apart and readily visible to any person approaching the property.
(C) When any owner or tenant of any lands shall post a notice as provided in this section, a proof of the posting is deemed and taken as notice conclusive against the person making entry for the purpose of trespassing.