With very few exceptions, most restaurants prohibit diners from bringing in outside food or drink — which makes sense, given what they exclusively sell: food and drinks.

Sure, there are bars in Toronto where meals aren't served that let you bring your takeout in, and restaurants where you can uncork your own bottle of wine for a fee.

You won't find many business owners, however, who'd allow you to bring a tupperware container full of leftovers into the space they pay so much money to lease and run, especially when there are other customers waiting for a table.

Heads up, people with dietary restrictions and allergies: You are apparently not the exception to this rule.

A rollicking conversation about whether or not people with allergies should be allowed to bring their own food into restaurants is taking place right now in the popular Food and Wine Industry Navigator Facebook group for bar/restaurant industry staffers.

"[I] had someone come in with a group today who said, 'If you don't mind, I'm going to eat my lunch while they eat theirs (ordered from the bar) because I have allergies," reads the original post from a group member.

"I told her that we do not allow outside food to be consumed in our restaurant and that in the future, they should check before to see a) that this is allowed or b) if we can accommodate their allergies rather than just assuming she could eat outside food at our place," the post continues. "The table was not happy and I apologized as much as I could."

The poster goes on to ask if there are any laws governing this type of situation in place. In just two hours, at least 70 people have replied to his query with thoughts and stories of their own.

"So entitled, so rude, so disrespectful. Do people need to be reminded that a restaurant is your livelihood?" wrote one. "It's not a cafeteria. There are ways as a customer to go about this in a mature and respectful manner, by being up front and asking questions before you go in and before you start opening your Tupperware. It's ridiculous."

Many people in the conversation have pointed out that there are better ways for those with food allergies to ensure they're safe at restaurants. Most servers and cooks will bend over backward to accommodate guests with special needs.

"I would politely enquire what their allergies were, quickly come up with a list of things they can eat off the menu, offer them those options," suggested one commenter.

"If they still chose not to take those options, I would simply say 'I'd really like to accommodate you and make sure you and your friends are having a great time, but this restaurant has a no outside food policy for liability reasons. I’m asking you to please respect this policy in return."

Indeed, it's not only money that drives restaurants to turn away diners who bring their own food — it's potential legal issues.

"Too many liabilities with outside food," noted one. "If she offered a bite to someone at the table without you noticing and they get sick they might blame it on the restaurant. I say gently ask them to leave."

Not everyone agrees with these "no outside food" policies, but some members of the group did come forward with suggestions to compromise.

"Typically when a guest consumes outside food in a restaurant they're charged a plating fee (most often with dessert, $3-5)," noted one commenter.

"Next time tell them it's $10 if they want to consume their food in your space, or they can explain dietary restrictions beforehand and give you a chance to accommodate them."

When push comes to shove, it's always best to call ahead and ask a restaurant about their policies before showing up to a hot bistro with a sandwich in your purse.