What does returning a received line based on a PO in Self Service Receiving actually do?

Summary:

For Transfer Orders, there seems to be some tie up with Shipping to create lines for items to be returned via Inventory. However, receipts for POs that are managed in Self-Service do not seem to have any outcome.

1) How is the user supposed to physically return the goods to the supplier?

2) Should a debit memo not be created automatically in case the invoice was paid?

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