Ohio Rev. Code Ann. § 3366.04
(D) The bond proceedings may contain additional provisions as to:
(I) In the discretion of the issuing authority, obligations may be secured additionally by a trust agreement or indenture between the issuing authority and a corporate trustee and, if so provided for in the bond proceedings, any other necessary or appropriate party. Any such trustee shall be a trust company, bank, or national banking association authorized to exercise trust powers within the state. Any such agreement or indenture may contain the order authorizing the issuance of the obligations, any provisions that may be contained in any bond proceedings, and other provisions which are customary or appropriate in an agreement or indenture of such type, including, but not limited to: