Achievements in Charming is a book about Charms. It can be read to revise for Ordinary Wizarding Levels.
Hermione Granger uses the book for this purpose, furiously rereading the book in order to make sure she had the material down before the exam. The day before the Theory of Charms O.W.L., she asks Harry Potter to quiz her; he does so, but soon regrets his decision when he finds that Hermione frantically retrieves the book after every quiz question in order to check that her answer is completely correct. She eventually hits him on the nose with the book's sharp edge. 
- Harry Potter and the Order of the Phoenix (First appearance)
Notes and references
- Harry Potter and the Order of the Phoenix - Chapter 31 (O.W.L.s)