Field help (PTHPOPLIN) 

This is the number of the purchase order line that originated the receipt line.
A receipt line can involve only one order line, it will therefore be necessary to enter this line number if the order number has been entered. Use the Actions icon to select one of the lines of the relevant order.
Once the order line is entered, certain fields will be automatically initialized as a function of the information entered at the level of the order line. It remains possible to modify certain fields and/or to enter additional information.
The order line number is not mandatory if the PTHDIR - Direct receipt parameter (ACH chapter, REC group) authorizes the entry of direct supplier receipts and if no order number has been entered.