Redstone Book is an item added by Bibliocraft. This book looks like a signed book when crafted.
Crafting
Uses
When this special book is placed on a bookcase, the bookcase emits a redstone signal. The bookcase will emit a redstone signal level based on the slot in the bookcase the book is placed. In the top left spot, the bookcase emits no signal, in the bottom right slot, the bookcase emits a level 15 signal. Any slot in between will emit that level of redstone, counting the first slot in the top left as slot 0. So a redstone book in slot 7 (top right) will emit a redstone signal with 7 strength. The book will also say it's by you, like when you look at a signed book.