I’ve posted this before but it’s worth repeating.
It’s important to remember they there is no obligation on anybody to prove that an exemption applies, according to the government’s own guidance.
Furthermore the guidance also makes clear that “exemption cards” are a matter of personal choice and not a legal requirement.
www.gov.uk
Exemption Cards
If challenged by someone in authority the correct approach is simply to state that an exemption applies. There’s no need to show evidence of this, and there’s no need to explain what that exemption might be. This has been my experience over the last few days travelling quite extensively and using various modes of transport, with no problems at all.
I would urge any forum members who are unable to wear face coverings to get out and about, as we are all now encouraged to do, keeping the above in mind.