gtin attribute
Invalid GTIN
A GTIN must be the manufacturer-assigned identifier for the exact product and variant, with a valid format and check digit.
Why this stays manual
Commerce Guardian flags identifier issues for review. It never repairs digits, borrows an identifier from a related item, or generates one.
What to verify
Check the product packaging or authoritative manufacturer data, confirm the variant, and remove the field only when Google’s rules say the product has no assigned GTIN.
Source: Google GTIN specification.