S.C. Code § 34-21-230
Each common trust fund shall be established and maintained in accordance with a written plan, referred to in this article as the plan, approved by resolution of the board of directors of the trust institution and approved in writing by competent legal counsel. The plan shall provide that the common trust fund shall be administered under the laws of this State and of the United States, and in conformity with the rules and regulations promulgated from time to time under authority of such laws, and shall contain full and detailed provisions, not inconsistent with the provisions of this article, as to the manner in which the common trust fund is to be operated, the investment powers with respect to the common trust fund, the allocation and apportionment of income, profits and losses, the terms and conditions governing the admission or withdrawal of investments or participations in the common trust fund, the auditing and settlement of accounts of the trust institution with respect to the common trust fund, the basis and method of valuing securities in the common trust fund, the basis upon which the common trust fund may be terminated, and such other matters as may be necessary to define clearly the rights of participants in the common trust fund. A copy of the plan shall be available at the principal office of the trust institution for inspection during all regular business hours to any person having an interest in a participation in the common trust fund. The plan may provide for the amortization of the premiums upon bonds or other obligations, the disposition of discounts and profits and the allocation of them or the apportionment of them between principal and income accounts, the establishment and maintenance of a reserve out of current interest from mortgage investments against which realized losses on mortgages may be charged, and other like matters. The provisions of the plan shall control all participations therein and the rights and benefits of all persons interested in such participations as beneficiaries or otherwise.
S.C. Code § 34-21-230