Birdwatchers' Map of Iceland

The percentage of alcohol present in an alcoholic beverage, expressed as a proportion of the total liquid volume. It indicates how strong the drink is and helps consumers compare products or comply with legal limits.

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.

The calendar date on which the product was first made available to the public or released for sale. It is expressed as a full year, month, and day (YYYY-MM-DD) and 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.