The Keys to the Universe Cards

The individual or group credited with creating the main content of a product, such as a book, film, or other creative work. The value is a free‑text string representing the name(s) of the primary creator.

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 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.