Guide Book
The Guide Book is the single item added by this library mod. It is not a normal book you craft for its own sake — it exists so that other mods can ship their own documentation inside your game.
When a mod uses this library, it registers its own guide content, and that content becomes readable through a Guide Book. Opening the book shows a table of contents built from the entries that mod has defined, and you navigate by clicking through categories and pages rather than flipping blindly.
Because the book is a container for other mods' content, what you see inside depends entirely on which mods you have installed. A Guide Book with no supporting mods registered will have little or nothing to show. If a mod you installed mentions a guide, this is the item it means.
Use it as an in-game reference: it saves you from alt-tabbing to a browser while playing.
