1. No bonds may be refunded hereunder unless the holders thereof voluntarily surrender them for exchange or payment, or unless they either mature or are callable for prior redemption under their terms within 25 years after the date of issuance of the refunding bonds. Provision must be made for paying the securities within that period.
2. The maturity of any bond refunded may not be extended beyond 25 years, or beyond 1 year next following the date of the last outstanding maturity, whichever limitation is later, nor may any interest thereon be increased to any rate which exceeds by more than 3 percent the Index of Revenue Bonds which was most recently published before the bids are received or a negotiated offer is accepted.
3. The principal amount of the refunding bonds may exceed, be less than or be the same as the principal amount of the bonds being refunded so long as provision is duly and sufficiently made for their payment.