The [GTIN-13](http://apps.gs1.org/GDD/glossary/Pages/GTIN-13.aspx) code of the product, or the product to which the offer refers. This is equivalent to 13-digit ISBN codes and EAN UCC-13. Former 12-digit UPC codes can be converted into a GTIN-13 code by simply adding a preceeding zero. See [GS1 GTIN Summary](http://www.gs1.org/barcodes/technical/idkeys/gtin) for more details.
Ожидаемые значения должны быть одного из этих типов
Text
Используется в таких типах
Offer
Product
Demand

Schema Version 1.1