The first time we saw it was in “Toy Story” on the license plate of the Pizza Planet truck.

It popped up again on a box in “A Bug’s Life,” but perhaps it was just a strange coincidence.

In “Finding Nemo,” it was on the diver’s camera. Something fishy was going on here.

It was also the coordinates for Mr. Incredible’s cell in “The Incredibles.”

It showed up twice in “Cars”: once on a train…

…and again on Mater’s license plate.

It was on a tag on one of the rats in “Ratatouille.”

And in “Wall-E,” it was the code signaling everyone to evacuate planet Earth.

You might have missed it as the courtroom number in “Up!” if you were too busy crying.

But don’t worry, you could spot it on a plane…

…on a screen…

…and again on Mater’s license plate in “Cars 2.”

Only the sharpest of eye could see it in Roman numerals above a doorway in “Brave.”

It was on a door in “Monsters University.”

But strangely, it also showed up in non-Pixar movies, such as “Lilo and Stitch.”

Here it is in “The Iron Giant.”

It’s coming right for you in “The Princess and the Frog.”

It’s easy to find in “The Brave Little Toaster.”

You can even see it in “The Avengers.”

TWICE!

It’s not just movies—it also makes appearances in TV shows such as “American Dad.”

It’s come up in “The Simpsons” more than once.

So what exactly is A113? A conspiracy? A secret alliance? A message to aliens?

Nah, it’s just the room number at the California Institute of Arts, where many animators (including plenty who now work for Disney and Pixar) got their start.

Putting A113 in their animations is kind of like a fist-bump to their classmates and to anyone who has ever and will ever learn about animation in that magical classroom where it all begins.