How to publish GTIN and MPN so AI systems can use them

Put them in the page itself: the GTIN and MPN as visible text near the product name, and the same values in the page's Product structured data. Use the full GTIN without spaces, one per sellable item, and make sure retailers publish the same numbers.

1. Visible text

Near the product name, as text rather than an image:

Model: Trail 45 · MPN TR-45-GRN · GTIN 00012345678905

Visible text is what a model reads when it quotes the page, and what survives when structured data is stripped or ignored.

2. Structured data

In the page's Product block, the same values in the fields meant for them: gtin13 (or gtin12, gtin14) and mpn, plus brand. The values must match the visible text exactly.

3. One per sellable item

A variant a buyer can order separately gets its own GTIN. Reusing one GTIN across variants tells every system that they are the same item.

4. The same numbers everywhere

Retail partners should carry the same GTIN and MPN in their feeds. A mismatch between your page and a retailer's is a mismatch a model has to resolve on its own.

5. Check

Fetch the page without JavaScript (curl -s <url>) and search the output for the GTIN. If it is not there, most crawlers did not see it either. The full checklist is at /checklists/product-identifiers; what a published identifier does and does not prove is at /evidence.