Easter egg: From the main menu, go to "Special Features" and then highlight "More" and press your Enter button. Select "Interior Reveals." The first egg is here. Highlight "Michelle Prepares To Go To Spain " and press your Left button to highlight the Alicia's eyes. Press your Enter button to view the alternate ending of the film. While on "Special Features" (the first page), highlight "Deleted Scenes" and press your Left button again to turn the lights red. Press your Enter button to watch some outtakes.
School of Rock (2003)
1 easter egg
Directed by: Richard Linklater
Starring: Jack Black, Joan Cusack, Mike White, Adam Pascal
Continuity mistake: In the scene where Dewey and Ms. Mullins are in the bar, the shots from behind Ms. Mullins sitting down show that her left hand is on the table. However, the shots showing the front of Ms. Mullins show her arms folded.
Ms. Mullins: I've just been informed that all of your children are missing.
Trivia: The final sequence during the credits was all unscripted. Both the dialog and music solos were improvised.
More questions & answers from School of Rock
Answer: It is never said but If I was to guess, they got it from the guy he was pretending to be (Ned's) information from the school office.