S.C. Code Ann. § 63-15-516: Nature of authority created by agreement.

(A) An agreement under this subarticle is temporary and terminates pursuant to Subarticle 4 following the return from deployment of the deployed parent, unless the agreement has been terminated before that time by court order or modification of the agreement pursuant to Section 63-15-518. The agreement derives from the parent's custodial responsibility and does not create an independent, continuing right to caretaking authority, decision-making authority, or limited contact in an individual to whom custodial responsibility is given.

(B) A nonparent given caretaking authority, decision-making authority, or limited contact by an agreement under this subarticle has standing to enforce the agreement until it has been terminated pursuant to an agreement of the parents under Section 63-15-518, under Subarticle 4, or by court order.