STEVE Dublanica has swapped your decaf coffee for regular, “crop dusted” your table with his intestinal gas and called the cops on you after you got drunk and staggered out to your car.

Lesson No. 1: “Waiters can and do spit in people’s food . . . I prefer more elegant methods of revenge.”

Dublanica is a waiter. Actually, he’s “The Waiter” behind the anonymous (until now) four-year-old blog Waiter Rant, and he’s got a new book of the same name out in stores today chronicling his nine-year career waiting tables in the city’s affluent suburbs (he won’t divulge the true identity of “The Bistro”). Anthony Bourdain has called it “the front-of-the-house version of ‘Kitchen Confidential,’ ” his stomach-churning restaurant exposé that changed the way New Yorkers ordered food.

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Similarly, whether you fear Dublanica or sympathize with him, you may think twice before treating him – or any other waiter – shabbily again. Because if you still insist on stiffing him after reading his book, he’ll just put a friendly little note (“customer’s an a – – hole,” perhaps) under your name in the Open Table reservation system. Good luck getting that 8 p.m. table next Saturday night.

Lesson No. 2: “If you never get the table you want at your favorite restaurant . . . someone at the restaurant doesn’t like you.”

Because if there’s anything to be learned from “Waiter Rant,” it’s that there are consequences to behaving like a self-entitled jerk.

“I think a misconception people have of me is that I treat everyone askance – that I give a hard time to every customer – but that’s not true,” says Dublanica over dinner one evening at Danny Meyer’s Eleven Madison Park. Dublanica, 40, is dressed in preppy khaki pants and a navy blazer.

“I would give a hard time only to the ones who deserved it.” Among the folks who have “deserved” to see Dublanica’s “thousand-yard waiter stare” are those who call him names, those who feign food poisoning to get out of paying the bill and those who make “unreasonable demands” (“‘Hi waiter, I want sushi.’ ‘Um, we’re an Italian restaurant, ma’am, we don’t have sushi.’ ‘But you have tuna, don’t you?'”).

Foodies are particularly irksome, according to Dublanica, “because they ask questions they already know the answers to.” (“You don’t have super-fancy balsamic vinegar, do you?”)

Lesson No. 3: “It’s gotten to the point where I can tell how much money I’m going to make off a customer within 10 seconds of meeting them.”

Of course, as any diner who has been treated unfairly in a restaurant knows, not everyone always gets the same level of service.

And profiling diners based on age, sex and race is still rampant in the industry. “I try not to fall into that trap,” says Dublanica. “I’ve had waiters say to me, ‘this group doesn’t tip well’ – whatever. I don’t believe that. The people who have given me the worst tips of my life have been white Anglo-Saxon males.”

Lesson No. 4: “Restaurants are places where people struggle to make a living.”

At Eleven Madison Park, a small army of servers caters to our every whim. Why would anyone want to ruin this bit of dinner theater with the sordid backstage details contained in Dublanica’s book?

For Dublanica, the answer boils down to responsibility. If you care whether the pig you are eating was humanely raised, shouldn’t you also care about the people preparing it?

“You need to know where your food comes from,” he says. “The same thing holds true for restaurants. You should know that the waiter doesn’t make a salary and a tip [or] that a good percentage of restaurants don’t treat their employees well.

“You’re always gonna have people who say [that] you should be lucky you get 10 percent – and those people are lousy customers and you don’t want them anyway. Then you’re gonna have people who genuinely don’t know [what goes on in the restaurant industry] and are interested and maybe they’ll be annoyed, like with Anthony Bourdain’s book.”

But even perfectly nice customers like “The Waiter” have to deal with the occasional dining snafu: When it’s time to leave Eleven Madison Park, we notice a charge for a $75 glass of dessert wine that was never ordered and is eventually removed from the bill.

Lesson No. 5: “Always examine the check!”

We leave in excess of 20 percent anyway. Maybe the waiter was just having a bad night.

Tonight at 7, Dublanica will sign copies of “The Waiter” at Borders Columbus Circle, at the Time Warner Center; (212) 823-9775.

carla.spartos@nypost.com