S.C. Code Ann. § 58-11-30

Under such rules and regulations as the commission may prescribe, every radio common carrier shall file with the commission and the Office of Regulatory Staff, within such time and in such form as the commission may designate, schedules showing all rates, rules, and regulations established by it and collected or enforced, or to be collected or enforced within the jurisdiction of the commission, and the radio common carrier shall keep copies of such schedules open to public inspection upon request at reasonable intervals during business hours under such rules and regulations as the commission may prescribe.