Sometimes you just want to get together with your friends. Wherever they may be.

But what if they're headed to a restaurant whose food you don't want? Maybe the eatery serves mostly meat when you're a vegetarian. Or they have nothing gluten-free. Or they only offer Coke when you prefer Pepsi.

If you do walk in with your own grub, know this: You are committing a grave offense in the view of many restaurant owners.

Jennifer Fidel, owner of Aunt Jenn's Tea & Spice Shop in Wilton Manors, has become so exasperated that she put a sign on her door stating, "No outside food or drink," because so many were bringing in their own coffee.

"People are not conscious of how inconsiderate it is," Fidel said. "They don't put themselves in the shoes of a small business owner."

Despite the sign, potential patrons still walk into the store with their own coffee or tea about once or twice a month, she said, to meet up with friends or buy tea or spices. At least that's down from three times a month before she posted the sign.

South Florida restaurant owners say this type of trespass is a problem that occurs regularly.

Jason Lakow, a partner in three Palm Beach County restaurants, including Tropical Smokehouse in West Palm Beach, said patrons carry their own alcohol into his eateries at least once a week, often in red Solo cups. His staff monitors the door and approaches all drink-holders.

"They are met with immediate confrontation," Lakow said. "We say, 'I'm taking this cup away from you' or 'you have to finish it outside.' "

The practice is not totally new. John Noble Masi, an assistant professor at Florida International University's Chaplin School of Hospitality & Tourism Management, remembers when his mother brought her own popcorn into movie theaters. And restaurants have for years charged corkage fees for patrons who want to drink their own wine.

But Masi said many Americans today have dietary restrictions, such as eating gluten-free or vegetarian or being allergic to nuts, diminishing the possibilities of what they can order at a restaurant.

At the same time, he said, restaurants started shrinking their menus after the COVID-19 pandemic to reduce food and labor costs, further dwindling diners' options.

Such cutbacks have affected many people who like to eat out, such as Mary Elizabeth Rivera of West Palm Beach.

"I have a lot of food allergies and recently have also had to go dairy-free, which is awful. I'm finding almost nothing on a lot of menus that I can eat so it's really challenging," Rivera wrote in "Let's Eat, South Florida," the Sun Sentinel's foodie Facebook group. "Oftentimes I'm finding that the very limited options aren't even things I like.

"For example, a plain baked potato with no butter or sour cream is the most unappealing thing in the world and I would rather starve than eat that. Or a weird vegan dish with virtually no protein that I would never eat is an option. It's just very limiting."

State law doesn't specifically prohibit outside food from being brought into restaurants, but several rules in the Florida Administrative Code make restaurants responsible for what's served on their premises.

One rule, in Chapter 64E-11 of the code, says: "Food received or used in food service establishments shall be from sources approved or considered satisfactory by the department and shall be clean, wholesome, free from spoilage, adulteration and misbranding, and safe for human consumption. It shall have been prepared, processed, handled, packaged, transported and stored in a sanitary manner so as to be protected from contamination and spoilage."

Outside meals entering the restaurant could have been put together in unsanitary conditions, Lakow said.

"If you ask us to heat up the food, that could be a health code violation for us," he said. "The way we stay safe and clean is by controlling variables."

A post in "Let's Eat, South Florida" asking about this bring-your-own trend revealed several categories of foods besides liquor that South Floridians admit to carrying into local establishments.

Birthday cakes: Most restaurants don't serve traditional big birthday cakes, but some have developed policies for guests who bring their own. Eddie Pozzuoli, co-owner of five restaurants in Palm Beach and Broward counties (including Eddie & Vinny's in Coral Springs and Dear Olivia in Parkland), said each of his eateries takes its own approach. Some charge a flat fee of $10, while others charge $2.50 per person.

Gluten-free food: Chris Tejeda, who operates TMI Food Truck with his wife, Erin Hayes-Tejeda, said he has noticed a "Bring Your Own Bread" trend, especially among those who say they eat gluten-free. He said his truck attends about five events a week and, at each event, at least one person will bring gluten-free bread. He warns them that the truck is not gluten-free, but he said they still want his food with their own provisions.

Soft drinks: People are very picky about what they will drink. Deerfield Beach resident Savannah Varner said, "I bring my own drink. Not because I'm cheap. But because I don't drink soda, nor do I care for anything offered on the drink menu. I usually bring a bottle or two of zero-sugar drinks that I like. I don't think it's wrong because I spend plenty on my food order and I tip generously."

George Brackett, of Hialeah, has a similar routine. He wrote: "I'm on a special diet made by my doctors, and can only drink Sprite Zero, so I normally have 2 bottles with me! If they don't allow me to have my own drinks that they don't have, then I just go to another restaurant!!!"

And Ellen Fried, moderator of several food-related Facebook groups including "Ellen Loves Pastrami," said she dines out almost daily and brings her own Diet Pepsi.

"It is almost always in fast-casual restaurants, where I order at the counter," she said. "And I usually tell them, 'I'm not a Coke gal, so I just brought my Diet Pepsi in here.' "

Condiments: Fried said she also has brought Russian dressing to restaurants as well as other flavorings.

"I've also been known to bring my own Breakstone's whipped butter into places that only serve margarine," she said.

Although some restaurants will tell customers to leave if they bring in foreign fare, many said they approach these situations with diplomacy.

"I'm not going to kick them out," said Fidel, owner of Aunt Jenn's Tea & Spice Shop. "I need to make the sale."