Echo

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.

The physical form in which a book is published, such as paperback, hardcover, audio CD, or board book. It indicates the binding style and overall durability of the product.

A collection of individuals who have contributed to the creation or publication of a product, such as authors, editors, illustrators, translators, or other creative personnel.

A brief statement indicating the edition or version of a product, such as "Reprint", "New Edition", or a numeric edition number like "2nd edition". It identifies which specific release of the item is being referenced.

The total count of individual pages contained in a book or printed publication. It represents the number of physical sheets that make up the product, regardless of layout or formatting.

The calendar date on which the product was first made available to the public or released for sale, expressed as a full year, month, and day (YYYY-MM-DD). This attribute can be used to filter or sort items by release period.

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

The age range or maturity level for which a book, educational material, or other content is intended, indicating the appropriate reader group based on comprehension and content suitability.