gtin¶
A Global Trade Item Number (GTIN). GTINs identify trade items, including products and services, using numeric identification codes.
A correct [[gtin]] value should be a valid GTIN, which means that it should be an all-numeric string of either 8, 12, 13 or 14 digits, or a "GS1 Digital Link" URL based on such a string. The numeric component should also have a valid GS1 check digit and meet the other rules for valid GTINs. See also GS1's GTIN Summary and Wikipedia for more details. Left-padding of the gtin values is not required or encouraged. The [[gtin]] property generalizes the earlier [[gtin8]], [[gtin12]], [[gtin13]], and [[gtin14]] properties.
The GS1 digital link specifications expresses GTINs as URLs (URIs, IRIs, etc.). Digital Links should be populated into the [[hasGS1DigitalLink]] attribute.
Note also that this is a definition for how to include GTINs in Schema.org data, and not a definition of GTINs in general - see the GS1 documentation for authoritative details.
Domain: Demand, Offer, Product
IRI: http://schema.org/gtin