From where does the tax details get populated in Purchase return?

Suggestion:
In Purchase return,In item details, we enter the details of the items to be returned to the supplier. Users enter the PO number against which this item was ordered, Purchase order number should be against the same supplier entered on header. Users then enter the line number of the Purchase Receipt for which the material is to be returned. The system sets the order line details of Purchase Receipt. Users have to select the item stock using the stock button then the tax details ,tax class, tax chapter, tax environment which was in receipt data comes automatically.
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