The following parameters are available in the tab Trade of the menu System → Configuration → Trade, which is described in the article Trade tab – General information.

Section Barcodes contains the following parameters:

• Check uniqueness of item barcodes – this option allows for enabling verification of uniqueness of barcodes for items. If a given barcode already exists, an appropriate message is displayed and the possibility of saving item form with duplicated barcode is disabled.
• Check uniqueness of pack barcodes – this option allows for enabling verification of uniqueness of barcodes for packs. If a barcode is duplicated, an appropriate message is displayed. The user can decide, whether packs with duplicated barcodes can be created or not.