In Toy Story, a license plate reads "A113," and it was also featured on a scuba diver's camera in Finding Nemo. It was front and center in Wall-E, and in the movie Brave, "A113" appeared as Roman numerals.
"A113" is actually the number of a classroom at the California Institute of Arts where many Pixar animators learned their craft. The number doesn't only appear in Pixar films, it has also appeared in an episode of The Simpsons as an inside joke.
Fandango correspondent Tiffany Smith told INSIDE EDITION, "You feel like you are a part of the game when you catch the little "A113." In Monsters University, it is actually the classroom number, which is actually a beautiful reference when it was the classroom at CalArts."
So, the next time you see "A113" in a move, the mystery will be solved.