Then of course there are those people who are either exempt or have a "reasonable excuse" for not wearing one. It seems the Obergruppenführer whom Retro was unfortunate enough to encounter today could not have coped with them.
I'm afraid "their house, their rules" does not quite apply here. An NHS hospital is a public place which in funded by the taxpayer. It's not a private bar or restaurant. The NHS should comply with the legislation and guidance laid down by the government. Despite hospitals being exempt from the legislation for visitors and outpatients to wear face coverings, on 5th June the government published this advice:
https://www.gov.uk/government/news/face-masks-and-coverings-to-be-worn-by-all-nhs-hospital-staff-and-visitors#:~:text=others%20from%20coronavirus-,Face%20masks%20and%20coverings%20to%20be%20worn%20by%20all%20NHS,face%20coverings%20at%20all%20times.
Among other things, it said this:
"Last month, government set out advice for people on how to make their own face coverings easily at home, using scarves or other textile items. These face coverings should cover the mouth and nose while allowing the wearer to breathe comfortably and can be as simple as a scarf or bandanna that ties behind the head to give a snug fit."
No mention that only approved types must be worn.
The guidance was updated last week but still the definition remains the same and there is no mention of only approved types of coverings being required anywhere. In fact NHS settings are specifically mentioned in the guidance (though not in the legislation) but still no mention of type approval.
There seems to be large numbers of people in various settings intent on making life unnecessarily and additionally unpleasant in this country. As a well known feature writer often maintains: if you give people who are unused to holding it a hint of power, they will always, always abuse it. It seems Retro encountered somebody modelling herself on Rosa Klebb at his local hospital this morning. Lotte Lenya would be proud.