Section 4--109. Process of Posting. The "process of posting" means the usual procedure followed by a payor bank in determining to pay an item and in recording the payment including one or more of the following or other steps as determined by the bank:

(a) verification of any signature;

(b) ascertaining that sufficient funds are available;

(c) affixing a "paid" or other stamp;

(d) entering a charge or entry to a customer's account;

(e) correcting or reversing an entry or erroneous action with respect to the item.