California Code, Government Code - GOV § 43782

(a) Determine that the public interest and welfare will be best served by the cancellation of all or part of the principal and interest of the bonds.

(b) Designate the issue of bonds to be canceled or the principal amount, numbers, and denominations of the bonds proposed to be canceled, if less than all.

(c) Fix the time and place of the proposed cancellation.  The ordinance is subject to referendum as other ordinances of the city.