2. Fortunately, libraries in the Middle Ages also numbered books, which told us its specific location, so the numbering system of each library was different.
3. The simplest numbering method is Roman numerals, such as the following Twelve Volumes. 4. Some libraries with few books are directly marked by letters, such as the small library in Bethlehem Abbey (near Brussels) in Belgium, where all books in Dutch in the Middle Ages are indexed by letters.
5. The first book in Bethlehem Abbey is a work of/kloc-0 in the late 4th century, written by the mysterious writer Hardevich. On the title page, we can still vaguely read the words "Visiones haywigis". A "means this is the first book on the shelf.