Finally! The hacks at the CBC have come around to pointing something out that people like myself, and many others have been saying for a long time. Save this article or keep it in mind to help inform other Canadians, because most of them won't listen to anything if it is not outright stated by their thought leaders at the CBC.

"While Ontario rules require masking inside all indoor public spaces, they also include exemptions for people who have difficulty wearing a mask or taking one off and on without help. The exemptions include children under two years old but also people who have physical or cognitive challenges that make mask wearing difficult. Anyone provided accommodations under Ontario's disability legislation and human rights code is also exempt from mask wearing.

Proof of exemption not required
The provincial exemptions are listed here on the website of the Middlesex-London Health Unit (MLHU) and there is no requirement to provide proof of an exemption.

Renneboog says her daughter's multiple disabilities mean she more than meets the criteria for an exemption.

"We wish she could wear a mask. Trust me, we do," said Renneboog. "She rips it off, gags and may vomit if she keeps it on. It could elicit a seizure in her."

Renneboog said Hailey's support worker tried in vain to explain the exemption policy with the Indigo employee at the door but eventually gave up and left."
https://www.cbc.ca/news/canada/london/her-daughter-has-a-mask-exemption-but-chapters-indigo-wouldn-t-let-her-in-1.5942044