Shipment on Invoice and Return Receipt on Credit Memo

What is the use of Shipment on Invoice and Return Receipt on Credit Memo on sales setup window .

Plz tell me iam little bit confused on how to n where to use them

You do not have to create a sales order and ship and invoice the goods. You can create a direct invoice for the items. If you do this you do not create a shipment record - unless you tick the shipment on invoice box, then the shipment record is also created. The same is true where you create a credit memo, instead of a return order.

Thank u Adam its very clear to me now

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