1.    The effect of the provisions of this chapter may be varied by agreement, but the parties to the agreement may not disclaim a bank’s responsibility for its own lack of good faith or failure to exercise ordinary care or limit the measure of damages for the lack or failure. The parties may, however, determine by agreement the standards by which the bank’s responsibility is to be measured if those standards are not manifestly unreasonable.

2.    Federal reserve regulations and operating circulars, clearinghouse rules, and the like have the effect of agreements under subsection 1, whether or not specifically assented to by all parties interested in items handled.

3.    Action or nonaction approved by this chapter or under federal reserve regulations or operating circulars constitutes the exercise of ordinary care and, in the absence of special instructions, action or nonaction consistent with clearinghouse and similar rules or with a general banking usage not disapproved by this chapter, constitutes prima facie the exercise of ordinary care.

4.    The specification or approval of certain procedures by this chapter does not constitute disapproval of other procedures that may be reasonable under the circumstances.

5.    The measure of damages for failure to exercise ordinary care in handling an item is the amount of the item reduced by an amount that could not have been realized by the exercise of ordinary care. If there is also bad faith, it includes any other damages the party suffered as a proximate consequence.