In the discretion of the city council, any bonds issued under this chapter may be secured or evidenced by an issuing instrument in the form of an indenture or a trust agreement between the city and a corporate trustee or trustees, which may be any trust company or bank having the powers of a trust company. An issuing instrument may contain any lawful provisions the city council determines to be reasonable and proper. (Ord. 2012-039 § 2)