Pocket Rough Guide Reykjavik:

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 covering or binding style of a product, such as paperback, hardback, softcover, or other variants. It indicates how the item is wrapped or protected and can include simple text descriptors like "Yes" for items that come with an additional protective cover.

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.

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