Dear @lubos,
currently Manager register debit notes linked to an inventory item as an adjustment and not as a decrease of purchases under inventory value summary. The only way to have a negative purchase is to register the credit note as a negative invoice but we cannot do this since in Italy we are closely linked to the rules of eInvoices.
Would it be possible to add a flag the this kind of registrations under debit notes in order to choose whether it should be accounted as a negative purchase (decrease of purchases) or as an adjustment?