Why is "Folded almanac" trending?

Wikipedia Overview

A folded almanac, sometimes called a physicians folded calendar, girdle book, or vade mecum, refers to a type of medieval English almanac consisting of multiple folios which are folded multiple times and bound together to create a dense yet compact vessel for information which would be used in medical practice. For durability and transport, folded almanacs would often have a cover of leather, a durable knitted cover, or be contained in a small box. These covers were necessary to protect the delicate folios from the constant wear of use and friction against the users clothing. Boxes would be necessary in climates prone to rainfall such as England. Attached to the outer cover, a cord would allow the almanac's user to easily transport and access the almanac by attaching it to their belt, however few covers or cords survive.