Used for: excluding or detecting invalid GTINs or EANs.
Used in: "IF"-statements.
A GTIN format is a combination of eight, twelve, thirteen or fourteen digits. The "GTIN is valid" rule checks if this is the case. The "GTIN is not valid" rule checks if the GTIN format is correct and takes the checksum in to account. This rule can be used to exclude invalid products for marketplaces for which GTINs or EANs are mandatory (such as Amazon). (The last digit of a barcode number is a computer check digit which makes sure the barcode is correctly composed. Using the checksum provided by GS1 the rule looks for any invalid GTIN or EANs.) More information about GS1 can be found here.