The Officers and Employees Retirement Board, as constituted under § 62-203, shall serve as the Board of the plan and shall administer the plan consistent with its duties under § 62-203 and the terms of this plan. The Board shall serve as the fund trustees and the assets of the fund shall be held in trust for the exclusive benefit of the members of the Officers and Employees Plan and this plan and their beneficiaries, and a reversion of fund assets or a return of City contributions is prohibited, except as otherwise provided by applicable law or IRS Revenue Ruling 91-4. The Board may use fund assets to pay the reasonable costs of administering the plan, consistent with the requirements of § 62-204.