The UK Government should create a scheme to legally recognise those exempt from face masks with official proof of exemption. Currently it’s difficult to enforce the face mask law without proof of exemption.
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This will allow those such as retail workers to challenge non mask wearing customers who aren't displaying an exemption. This will stop the people who believe that covid-19 is a conspiracy, being defiant, above the law etc. from disrespecting other customers and workers who are willing to wear masks to protect themselves and others. Personally I have had several customers feedback saying that when other customers who aren't displaying exemption and aren't wearing a mask it makes them feel exposed and vulnerable.