Is it the link between the Invoice and the ~serialNumber of the scannable-at-a-distance Product? Most barcodes today only encode a ~sku (and not a serial numbe

Is it the link between the Invoice and the ~serialNumber of the scannable-at-a-distance Product? Most barcodes today only encode a ~sku (and not a serial number). Minimally, to lookup additional product information from just an sku (similar to a shorturl app), consumers would need an API to retrieve and/or lookup from a conjunction of per-Organization named graph documents linking schema:Things' ~schema:identifiers with the RDF subject URIs of NutritionInformation records. - P: schema:nutrition - d: MenuItem,Recipe - r: NutritionInformation - C: NutritionInformation https://schema.org/NutritionInformation https://schema.org/NutritionInformation C: https://schema.org/Offer https://schema.org/Offer supersedes the GoodRelations vocabulary for Products and Services: > For GTIN-related fields, see Check Digit calculator and validation guide from GS1.