Refunding bonds shall be issued pursuant to an authorizing resolution of the governing body of a governmental unit. Refunding bonds may be issued in one or more series, may bear such date or dates, may mature at such time or times (either serially or term or a combination thereof), may bear interest at such rate or rates not to exceed that allowed by law for the class of bonds being used to effect the refunding, may be in such denominations, may be in such form (either coupon or registrable as to principal or fully registered or a combination), may carry such registration and conversion privileges, may have such sinking fund provisions, may be executed in such manner, may be payable in such medium of payment and at such place (either within or without the state) at such time or times, may be subject to such terms of redemption (with or without premium), may be declared or become due prior to the maturity date thereof, may be sold at public or private sale (which sale shall be on such terms and in such manner as the governing body shall determine), may provide for the replacement of mutilated, destroyed, stolen or lost bonds, may be authenticated in such manner and upon compliance with such conditions, and may contain such other terms and covenants (including, without limitation, covenants for the security and better marketability of such refunding bonds), as may be provided by resolution of the governing body of the governmental unit.