"Grasp your broom firmly by the tail..."
—An excerpt of this text[src]

The Handbook of Do-It-Yourself-Broomcare is a manual that comes with the Broomstick Servicing Kit. Page twelve details a tip called A Charm to Cure Reluctant Reversers.

Handbook broomstick

The book in the broomstick servicing kit

Harry Potter received this book on his thirteenth birthday as a present from Hermione Granger. He tried to keep his cool during a visit from his Aunt Marge by focusing on this handbook.