(1) Public obligations evidenced by multiple bonds, notes, certificates or other instruments of the same issue shall be equally and ratably secured, without priority by reason of number, date, date of sale, date of execution or date of delivery, by any pledge or lien created or granted on collateral to secure the payment thereof, unless otherwise provided by the official action authorizing such public obligations.
(2) Any pledge or lien on collateral created or granted by an issuer shall be junior in priority to pledges, liens and other security interests created or granted prior to the date such pledge or lien is created or granted; provided, that an official action may provide for the issuance of additional public obligations on a parity with, or senior to, the public obligations authorized thereby.