Tab allows you to enter Billing Address within Purchase Orders Entry.   When you create a new PO, the billing address is automatically defaulted to values set in Facility Information,  Billing Address tab.  You can edit the address here for the specific PO.

BUTTONS:

Set Billing Address to Shipping Address: Copies data entered on Shipping Address Tab to Shipping Address

Set Billing Address to Facility Default Billing Address: Sets address to defaults set in  Facility Information, Billing Address