The Sign of the Four

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.

The pixel dimensions of a display or image, expressed as width by height (e.g., 1920x1080). It indicates how many pixels are used to render the visual content and is commonly used for monitors, TVs, smartphones, cameras, and digital images.

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

The mass of the product expressed in a standard unit such as grams or kilograms. It represents how heavy the item is and can be used for shipping calculations, handling instructions, or consumer information.