HER

Indicates the physical or digital format in which a product is presented, such as "Hardback", "Paperback", "DVD", "Blu‑ray", "Vinyl", or other media types. The value may contain multiple comma‑separated items to represent combined attributes (e.g., "Hardback, Illustrated").

A unique identifier assigned to books and other printed publications, typically consisting of 10 or 13 digits. It may include hyphens for readability but is treated as a string value. The ISBN uniquely identifies a specific edition of a title across the publishing industry.

A list of the natural languages in which a product is available or supported.

The name of the entity that publishes or distributes the product, such as a book, magazine, or other media item.