(1) No guaranty of an indebtedness which either is not written on, or does not expressly refer to, the instrument or instruments being guaranteed shall be valid or enforceable unless it is in writing signed by the guarantor and contains provisions specifying the amount of the maximum aggregate liability of the guarantor thereunder, and the date on which the guaranty terminates. Termination of the guaranty on that date shall not affect the liability of the guarantor with respect to:
(a) Obligations created or incurred prior to the date; or (b) Extensions or renewals of, interest accruing on, or fees, costs or expenses incurred with respect to, the obligations on or after the date.
(2) Notwithstanding any other provision of this section, a guaranty may, in addition to the maximum aggregate liability of the guarantor specified therein, guarantee payment of interest accruing on the guaranteed indebtedness, and fees, charges and costs of collecting the guaranteed indebtedness, including reasonable attorneys' fees, without specifying the amount of the interest, fees, charges and costs.