Standard metafield definitions

Standard metafield definitions are metafield definitions that we've created for some common use cases. If you need to store data for one of these use cases, then we recommend using the standard metafield definitions, because they are interoperable across the entire Shopify platform and connect more seamlessly to themes.

Learn more about metafield definitions.

The following table describes the standard metafield definitions:

Standard metafield definitions
Name Type Description Allowed resources Reserved namespace and key
Product subtitle single_line_text_field

Stores a concise description of a product. All apps should use this metafield instead of the product’s full description when a brief product summary is needed. For example, SMS apps can use the product subtitle for short text messages about a product.

Maximum length: 70 characters

  • PRODUCT
  • PRODUCTVARIANT
descriptors.subtitle
Care guide multi_line_text_field

Stores detailed instructions on how to take care of clothing. Themes aimed at merchants selling apparel can use this metafield for display on product detail pages.

Maximum length: 500 characters

  • PRODUCT
  • PRODUCTVARIANT
descriptors.careguide
ISBN single_line_text_field Stores an ISBN book identifier. Themes supporting booksellers can use this metafield to identify books to customers. Apps helping to merchandise books should write to this metafield for optimal theme integration.

Must be a 10-digit or 13-digit number (with optional hyphens).

  • PRODUCT
  • PRODUCTVARIANT
facts.isbn
UPC single_line_text_field

Stores a Universal Product Code (UPC). Apps reading or writing UPCs should integrate this standard metafield for display purposes, or for integration with ERP systems.

Must be a 12-digit number with at least one zero.

  • PRODUCT
  • PRODUCTVARIANT
facts.upc
EAN single_line_text_field

Stores a European Article Number (EAN). Similar to UPCs, apps reading or writing EANs should integrate this standard metafield for display in online stores, or for integration with ERP systems.

Must be a 13-digit number.

  • PRODUCT
  • PRODUCTVARIANT
facts.ean
Product rating rating Stores the average rating for a product or variant. Product rating apps should write to this standard metafield, and should update this standard metafield whenever a product’s rating has changed. Themes displaying product ratings should reference the product rating for the aggregated average product rating (stored as a rating type).
  • PRODUCT
  • PRODUCTVARIANT
reviews.rating
Product rating count number_integer Stores the total number of ratings for a product or variant. Product rating apps should write to this standard metafield, and should update this standard metafield whenever a product’s rating has changed. Themes that display product ratings should reference the product rating count for the total number of ratings for a product (stored as a number_integer type).
  • PRODUCT
  • PRODUCTVARIANT
reviews.rating_count