Pay on Receipt - Progressive Payments

Hello,

So an approved Work Confirmation replaces the need to enter receipts as that is being viewed as receipt of work. So if I set the Pay On option on the supplier record withiin the Key Purchasing Setups to Receipts (see screen capture), will Payables automatially generate an invoice for the work confirmation once it is in an approved status?

Also, does anyone know what the "Receipt and Use" value means? The Payables manual does not provide a definition for Receipt and Use or Use values.

Thanks,

Anthony