gtin constant

gtin [Expects: https://schema.org/Text, https://schema.org/URL]

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.

Can be used on: https://schema.org/Demand, https://schema.org/Offer, https://schema.org/Product