This button

Does this

Lock Book

Locks the book so other users cannot make changes, and puts the book contents into edit mode - enabling you to add, remove, or change content.

Unlock Book

Unlocks the book, making it available to other users, and takes the book out of edit mode. If changes to the book's contents have not been saved when you choose Unlock Book the changes will be discarded.

Save Book Contents

Saves changes made to the book's structure.

Create New Topic

Creates a new topic in the book.

Insert Existing Topic

Inserts an existing topic from the library into the book.

Reload Book Contents

Refreshes the book's content pane.

Promote

Promotes the selected object in the book's content pane, moving the object toward the book's root level.

Demote

Demotes the selected object in the book's content pane, making it a child of another object.

Move Up

Moves the selected object up a place in the book's content pane.

Move Down

Moves the selected object down a place in the book's content pane.