|This article is non-canon.
This article covers a subject that has been deemed non-canon by either the author or the Harry Potter licensees, and thus should not be taken as a part of the "real" Harry Potter universe.
- "No music is to be played during study hours."
- —The Decree[src]
The Educational Decree Number Twenty-Four was the first Educational Decree created by Dolores Umbridge, then-Hogwarts High Inquisitor. This Educational Decree forbade the playing of music during the students' study hours. 
Behind the scenes
- As the numbering for this Educational Decree is not consistent with the numbering established in Harry Potter and the Order of the Phoenix, it cannot be considered canonical.
- In the film adaptation of Harry Potter and the Order of the Phoenix the actual Educational Decree Number Twenty-Four is numbered sixty-eight, as this and several other non-canonical decrees are passed before it.
- Harry Potter and the Order of the Phoenix (film) (First appearance)