The first setting provides an option for Bill approval if the Bill has not been matched to its corresponding PO(s). This option is based on a specific amount, which can be set by the Administrator. The amount limit will determine if the Bill can be approved only after having first been matched to its corresponding PO(s).
The second setting regulates whether or not Bills can be approved even if the Bill amount exceeds the initial PO amount. The Administrator can set the amount limit for Bills so that they can exceed the PO by a certain amount and still be approved.
The third setting can regulate whether or not Bills can be matched to PO(s) that were issued later than the corresponding Bill.