(a) District bonds may be secured by a pledge of all or part of the district's revenue, or by all or part of the payments or rentals under one or more contracts or leases specified by board resolution or a trust indenture securing the bonds.(b) A resolution authorizing the issuance of bonds secured by a pledge of revenue of all or part of the district's facilities may provide that the district shall first pay the expenses of operating and maintaining all or part of the facilities as the board considers appropriate before paying the principal of and interest on the bonds.(c) A resolution authorizing the issuance of bonds secured by revenue, contract payments, or lease rentals may reserve to the district the right, under conditions specified by the resolution, to issue additional bonds that will be on a parity with, superior to, or subordinate to the bonds then being issued. Added by Acts 2007, 80th Leg., R.S., Ch. 920 (H.B. 3166), Sec. 1.06, eff. April 1, 2009.