S.C. Code Ann. § 33-46-310

A telephone cooperative by vote of a majority of the incorporators when originally organized or thereafter by vote of three-fourths of the members present in person or by proxy at a regular or special meeting of the telephone cooperative may elect to have the ownership interest in the telephone cooperative represented by shares, by certificates of membership, or by other evidence of membership. The rights and responsibilities of the members are as defined in the bylaws. No member except a telephone cooperative shall own more than one-fifth of all shares or certificates of membership of the telephone cooperative.