identifier_exists

`identifier_exists: false` is the explicit declaration that a product doesn't have manufacturer-assigned identifiers (GTIN, MPN, brand). Used correctly, it's the clean way to handle GTIN-exempt products — custom-made, vintage, original art, antiques, own-brand products without an assigned barcode. Used incorrectly, it's a bypass that flags as misuse during quality audits.

The legitimate use cases are narrow. A made-to-order jewellery piece has no manufacturer GTIN — `identifier_exists: false` is correct. A vintage clothing item from 1985 has no current GTIN — `identifier_exists: false` is correct. A standard branded retail product where you just haven't sourced the GTIN — `identifier_exists: false` is wrong; the GTIN exists and you need to find it.

Channels audit identifier_exists usage. Accounts using it heavily on what should be branded products eventually face account-level quality reviews. The signal channels look for: brand field populated, GTIN/MPN missing, identifier_exists: false. That combination is suspicious for retail. For genuinely exempt products, the combination is brand populated (your store name), GTIN/MPN missing, identifier_exists: false — and the product type is something that legitimately wouldn't have an identifier.