S.C. Code § 33-49-650
The bylaws may provide that in lieu of electing the whole number of trustees annually (a) the trustees shall be divided into two classes at the first or any subsequent annual meeting, each class to be as nearly equal in number as possible, with the term of office of the trustees of the first class to expire at the next succeeding annual meeting and the term of the second class to expire at the second succeeding annual meeting or (b) the trustees shall be divided into three classes at the first or any subsequent annual meeting, each class to be as nearly equal as possible, with the term of office of the trustees of the first class to expire at the next succeeding annual meeting, the term of the second class to expire at the second succeeding annual meeting and the term of the third class to expire at the third succeeding annual meeting. At each annual meeting after such classification a number of trustees equal to the number of the class whose term expires at the time of such meeting shall be elected to hold office until the second or third succeeding annual meeting, as the case may be, and until their respective successors shall have been elected and duly qualified.
S.C. Code § 33-49-650