It is used to specify, for this particular entry transaction, if the fields relating to the Spanish VAT (Customs date, Customs and Customs BP) must be:
The display or not of these fields in the Management section of the invoice is also dependent on the value of the SPAVAT - Spanish VAT company parameter (LOC chapter, SPA group) that specifies if the Spanish VAT is displayed or not. If this parameter is set to "No" for the company which the invoicing site is dependent on, these fields will not be displayed, regardless of the entry transaction setup.