Google has the gtin12 property to the Google product structured data documentation in its help center. Note, the gtin12 property was always supported but Google just didn't have it in the documentation until today. Google also clarified that you can use the generic gtin property for all GTINs, but Google said it recommends that you use the most specific one if possible.
It now reads "Include all applicable global identifiers; these are described at schema.org/Product. While you can use the generic gtin property for all GTINs, we recommend that you use the most specific GTIN that applies to your product, as this is the most accurate representation of the product. Make sure the GTIN value is in the numerical form; we don't support the URL form for GTINs."
Naomi Gallula posted on Twitter:
🚨🚨Another update on the GTIN property in the product structured data documentation- You can use the general property "gtin" in your Structured data but Google still recommends to specify and be accurate with the gtin applied to your product(gtin8,gtin12etc.) FYI-@rustybrick pic.twitter.com/9A7PHLvy1s
— Naomi Gallula (@naomig84) August 11, 2022
I completely agree with you- wired that Google is not aligned with it.
— Naomi Gallula (@naomig84) August 11, 2022
The Google side of it stems from an editorial oversight by me in updating /gtin definitions in a recent https://t.co/ooIuC1elTy release. I neglected to add the planned change to support URL gtin values. That fix is in progress but it'll take a while to propagate through...
— Dan Brickley (@danbri) August 11, 2022
Forum discussion at Twitter.
