(NEXSTAR) — In-N-Out is harboring a not-so-hidden secret about its restaurants, and no, it has nothing to with “animal-style” fries. Everybody already knows about those.

Look closely at the landscaping at most In-N-Out locations, and it’s likely you’ll notice at least a few palm trees planted around the perimeter. But two of those palms might seem slightly crooked, with crisscrossing trunks that form the shape of an “X.”

That “X” is entirely intentional — and it’s a nod to one of the founder’s favorite films.

“The founder of In-N-Out Burger, Harry Snyder, wanted to choose a symbol that would set In-N-Out apart from other restaurants,” explained Kathleen Luppi, In-N-Out’s communications specialist. “He decided on an idea he picked up from the movie ‘It’s a Mad, Mad, Mad, Mad World’ from the early 1960s.”

The movie, released in 1963, concerns a group of motorists on a mad dash to a state park in California, where they believe a secret stash of cash is waiting for them underneath a “big W.” Toward the end of the film, the group arrives at the park and finds a formation of palm trees in the shape of a W, marking the spot of the treasure.

In-N-Out founder Harry Snyder liked the idea so much that he began planting palm trees outside of his restaurants in 1972 — albeit in the shape of an X instead of a W — to mark the spot of his own symbolic “treasure,” according to an official online history of In-N-Out.

In-N-Out’s website also makes a point of specifying that “most” of its restaurants — not all of them — feature the crisscrossing palms, so it’s possible your nearest location won’t have any funky-looking trees to discuss with your dining companions.

In that case, don’t worry. You can still make conversation about In-N-Out’s “secret” item for dogs, or its keto-friendly Flying Dutchman burgers. Really, just try to talk about anything other than animal-style fries, because, again, everybody already knows about those.