Mastery

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 binding style of a book or similar printed product, indicating how the pages are held together and presented to the reader. Common values include "Paperback", "Hardcover", "Softcover" and other variations such as "Trade Paperback" or "Pocket Book". This attribute helps customers identify the physical construction and durability of the item.

The natural language in which a product’s content, user interface, or documentation is presented. It indicates the primary linguistic context for text, subtitles, audio tracks, and other language-dependent features.

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.