TORONTO -- Vegan restaurant owner Melanie Boudens proudly excludes dairy, eggs and meat from her menu but it's still full of references to cheese, mayo, bacon and sausages.

At the same time, large letters on her storefront and at the top of her menu declare the food "100 per cent vegan" and quirky spellings for "chick'un" and "bacun" signal that these are not your traditional comfort staples.

Nevertheless, Boudens says her Kanata, Ont., eatery has come under the scrutiny of the Canadian Food Inspection Agency after a customer complained of being misled by the description of a dish.

The flap has baffled Boudens, who says she has no intention of deceiving anyone at Grow Your Roots and believes she had "covered her bases" with multiple disclaimers.

She recalls facing off against a woman who complained about a coconut-based product that is listed on the menu as "cheddar cheese," without qualifiers.

"Word for word, I said, 'Well, I think I can call it whatever I want to call it,"' she says from her home in nearby Ashton, Ont. "But I guess I was wrong, I can't call it whatever I want."

Vancouver lawyer Anna Pippus says she's seen similar run-ins with the CFIA across the country, including the recent case of a small Vancouver vegan cheesemaker told to stop describing her products as cheese and a Quebec bakery called out for the way it described its vegan cheesecake.

Pippus is also director of the Plant-based Policy Centre, and she says her advocacy group is looking at launching a constitutional challenge in the coming months, believing the matter to be "a clear freedom of expression case."

Vancouver litigator Arden Beddoes of the firm Arvay Finlay is leading the legal team and says the case would look at section 5 of the Food and Drug Act, which says food labels should not be false, misleading or deceptive.

However, if the purpose is to ensure people aren't tricked, some of the current restrictions are too broad and the language outdated, Beddoes argues.

"What the regulation also contains is effectively a prohibition on using the word 'milk' in respective of anything that doesn't come from a cow," says Beddoes, who specializes in constitutional public law.

In addition to the Act, he points to detailed regulations that further specify what dairy products must consist of, such as the moisture content of gruyere. While he supports such efforts aimed at protecting producers and consumers, he notes a lack of similar definitions for vegan foods and the ingredients used to make them, for instance soy.

"If the regulation is about ensuring consumers are protected, why does it not even cover this vast group of products that are now very common?"

Pippus says definitions employed by the CFIA are decades-old and pre-date today's proliferation of plant-based beverages such as those made from soy, coconut, oats and nuts.

The CFIA website defines milk as "the normal lacteal secretion, free from colostrum, obtained from the mammary gland of an animal," while dairy products such as butter, ice cream and cheese are "foods produced from the milk of mammals."

That makes it difficult for plant-based producers to market and label their products, and difficult for consumers to purchase any plant-based products they're looking for, says Pippus.

A media relations officer for the CFIA said a spokesperson was not immediately available and referred questions to the agency's website, which details labelling guidelines. They include the directive that, "a dairy product that deviates from a prescribed standard may not use the common name associated with that standard unless the standardized common name is modified to indicate how the food differs in every respect."

Beddoes questions whether the average consumer really has such a hard time distinguishing between animal and vegan products.

"On its face you can be deemed to be in violation if you say, 'Oh, I'm selling cashew cheese' because you're using the word cheese," he says. "But are you actually tricking people or is anybody actually deceived?"

Boudens says an agent from the CFIA visited her restaurant and suggested adding more qualifying words to the menu, such as changing a reference to "cashew mozzarella" to "cashew mozzarella-style" and "mayo" to "mayo-style sauce." She says the agent was also unsatisfied with a reference to a "GYR Burger" but did not suggest an alternate name.

Boudens says she asked for a list of acceptable terms in email and has yet to receive them. Until then, she says she's not adding "a lot of extra words that are just kind of unnecessary."

"I don't feel obligated or under pressure to change the menu or anything," says Boudens, estimating that more than half her diners eat meat and likely need familiar terms to help them understand her non-traditional dishes.

"People need to understand that we're not trying to hide anything. I'm very proud of the ingredients that I use in my restaurant. It's all healthy alternatives to everything."

If it seems like vegan outlets get a disproportionate amount of scrutiny -- as Pippus believes -- it's because "people who are doing things that are less traditional are going to experience a greater degree of regulatory enforcement than those who are doing traditional activities," says lawyer Glenford Jameson, who runs a food-focused practice in Toronto, called G.S. Jameson and Company.

"The CFIA is not out to get anyone. The CFIA is, generally speaking, science-driven, a very fair agency that has insanely broad policy goals and also an enforcement agenda," says Jameson, who also teaches Canadian food law and regulation at Michigan State University.

Nevertheless, Pippus expressed frustration over what appears to be the CFIA's ad hoc approach to individual cases, saying producers like Boudens are essentially told to come up with their own descriptions: "There are no real proactive answers or clear sense of how the language can be used."

Earlier this year Canadian cattle producers in Quebec raised concerns about branding used by plant-based giant Beyond Meat, arguing it's misleading to use the word "meat" when advertising the California company's burgers. In a statement in May, the company said it intends to respect all Canadian norms.

Compared to the same conversation unfolding south of the border, Jameson considers the Canadian approach to be relatively flexible, pointing to U.S. battles such as one waged by a state senator who recently sponsored a bill banning meat words.

"There's actually a fairly sensible, reasonable consumer test that's performed by the regulatory body to see if something is really creating an erroneous impression or not and I think that's really helpful because in a lot of jurisdictions they're simply unwilling to have a discussion about it," he says.

Pippus suggests that if a phrase has entered common usage that's enough to make the case for its broader adoption.

"I make my kids (vegan) grilled cheese. I don't make them grilled cheddar-style sandwiches because that would be ridiculous. We're just calling it grilled cheese just like their friends have and this is a good thing," she says.

"It promotes a common language and social cohesion and prevents confusion."

On the other hand, having to "decipher the codes on the labels" of plant-based foods is confusing, she says.

"When it comes to some of these other alternative products -- sour cream, cream cheese, yogurt -- there is a little bit more capacity for confusion," Pippus says.

"'Cultured cashew spread,' for example. Well, what is that? Do I put that on perogies? Do I spread that on toast? Do I eat it with a spoon? What is this?"

The Dairy Farmers of Canada declined to comment, but said in an emailed statement that its members "fully support the rules put in place by the Canadian Food Inspection Agency regarding food labelling standards."

Pippus says for many years the food guide referred to "milk and alternatives" and "meat and alternatives," phrases that are widely disliked by the vegan community.

"Language is very powerful. What that does is it says: 'You Hindu vegetarians, you Buddhist vegetarians, you ethical vegetarians, you lactose-intolerant people -- you are alternative. You are different. You are not really of the mainstream. You're not part of us.' This is a problem for social cohesion in a diverse country."