70 ILCS 1831/70
All bonds, whether general obligation or revenue, shall be issued and sold by the Board in such manner as the Board shall determine. However, if any bonds are issued to bear interest at the maximum rate of interest allowed by Section 60 or 65, whichever may be applicable, the bonds shall be sold for not less than par and accrued interest. The selling price of bonds bearing interest at a rate less than the maximum allowable interest rate per annum shall be such that the interest cost to the District of the money received from the bond sale shall not exceed the maximum annual interest rate allowed by Section 60 or 65, whichever may be applicable, computed to absolute maturity of such bonds according to standard tables of bond values.
70 ILCS 1831/70