Written Book

Written books are an item created after a book and quill is signed. It appears as the same red book, but without the quill, and has an enchanted-looking glint.

Signing a book and quill
Written books can be obtained by signing a book and quill. After it has been signed, it cannot be edited again. The label does not say "Written Book", but what the player titles it. It will say the title on the top line of the label, and "by " on the bottom.  is the username of the player who signed the book. In Bedrock Edition, this is customizable without commands.

Usage
Written books can be opened by right-clicking (or holding down on the screen in Bedrock Edition), and will display a GUI allowing the player to read it or turn the page.

The contents of a book are an extra set of data attached to the item. This means that when a book is destroyed, its contents are lost with it.

Lecterns
One can place a written book on an empty lectern.

The lectern then emits a redstone signal depending on the displayed page in the book. On the last page, the lectern emits a signal strength of 15.

Item data

 * : The item's tag tag.

Trivia

 * When written books are obtained with commands (without the correct data tag), the label will only show "Written Book" and will have the text "*Invalid book tag*" when opened. The book is signed and cannot be edited without commands.
 * Commands which were added to a written book using serialized JSON objects will be executed through the chat system. This means that any command added to a written book can't be longer than 256 characters, which is the maximum chat line limit.