French Canadians are notoriously very protective of their language, and the Charter of the French Language (La charte de la langue française), also known as Bill 101 (Loi 101), is a law in the province of Quebec erecting French as the official language and defining the language policy.
In particular, product labels, instructions, manuals, warranty certificates, restaurant menus, wine lists, catalogs, brochures, signs and posters must be in French, although it is permitted to have them in other languages (usually English of course). There are a few exceptions to the rules, but the “language police”, the Office québécois de la langue française, is pretty strict.
Companies don’t have to change their name though, so Apple is not Pomme, but KFC somehow decided to operate under PFK (Poulet Frit Kentucky) and Starbucks is opening shops under the name Café Starbucks.
On April 27, 2015, the Québec Court of Appeal ruled in favor of several retail chains including Best Buy, Costco, Gap, and Wal-Mart, and concluded that the Charter of the French Language allows English trademarks to be used on public signage without adding any French term.
Two months later, Hélène David, Minister responsible for the Protection and Promotion of the French Language, announced that the corresponding Regulation would be amended in the fall and make mandatory the addition of French language generic terms, descriptive terms or slogans.
As the new Regulation (yet to be finalized) will take effect sometimes in 2016, retailers will probably have to update a lot of signage in all their stores!
One last point regarding trademark symbols, ®, TM, MD and MC can be used interchangeably in Canada from a legal standpoint (MD means Marque déposée or registered trademark, and MC means Marque de commerce or trademark). It is however safer to use both English and French symbols (TM and MC) in order to properly claim trademark rights, regardless of the consumer’s language.