The Vendor Contact Site List form open when you click the the Vendor Contact Sites button in Ship From Information in Purchase Order form. This form will list each Vendor ID that you have entered either a Contact or Site record for. You would initially setup in the Vendor Contact Sites and Department in the vendor form for a specific vendor. Then, this form will display a line item of information for each vendor and the total number of Contact and Sites for every vendor.
If you click on the ellipse button to the left of a specific Vendor ID or line item, the Vendor Contact Sites and Department form will open, which will allow you to view the contacts and sites as well as additional information.