I ate a McDonald’s cheeseburger here in Port St. Lucie and noted that it had mustard on it, as McDonald’s cheeseburgers seem to everywhere besides New York.

Curious, I searched Google and found only this post from Serious Eats, noting the same issue and asking commenters to describe the toppings on McDonald’s burgers in their region. Just about everyone from outside New York who responded said their burgers included mustard.

I asked Twitter, and @MaryL1973 suggested I contact McDonald’s. So I sent an email to everyone in the chain’s U.S. media-relations department asking why it was that New York-area McDonald’s don’t have mustard, where the dividing line is, and if there are any other regional variations on standard burger toppings.

About a half-hour later I received a statement from Jennifer Nagy, the McDonald’s Marketing Manager for the New York Metro region. It reads:

Approximately 85 percent of McDonald’s restaurants are owned and operated by independent businesspeople. As independent owners, McDonald’s franchise owners have the authority to make certain operating decisions as they relate to their McDonald’s restaurant operations. Because of regional preference, mustard is not added to the hamburgers in the New York Tri-State area, but customers are able to request mustard when ordering their favorite McDonald’s hamburger.

This reminds me of a Mitch Hedberg joke: “Every McDonald’s commercial ends the same way: Prices and participation may vary. I wanna open a McDonald’s and not participate in anything. I wanna be a stubborn McDonald’s owner. ‘Cheeseburgers? Nope! We got spaghetti, and blankets.'”

Anyway, there you have it: Individual franchise owners can make “certain operating decisions,” and apparently all the individual owners in the New York area have opted to serve their burgers without mustard standard. I suppose there’s some reasonable chance one guy or one group owns most of the New York-area McDonald’s and hates mustard, and that the few remaining McDonald’s not owned by that guy stopped serving mustard on burgers because too many New Yorkers complained. Something like that.

I suppose the big news here is that burgers without standard mustard are apparently a “regional preference.” I happen to like mustard on burgers (McDonald’s included), but probably not enough to request it at the drive-thru.