No contract, agreement, or other object involving the expenditure of money shall be entered into, nor shall any ordinance, resolution, or order for the appropriation or expenditure of money be passed by Council unless the Finance Director shall have first certified that the money required for the contract, agreement, or other obligation, or to pay the appropriation or expenditure, is in the treasury to the credit of the fund on which it is to be drawn and not appropriated for any other purpose. However, this rule does not apply to special improvements to be raised by assessment of property owners or for which an issue of bonds is to be provided.
(1980 Code, § 31.16)