> I think "fixme" is what Everydoor adds when you choose something that isn't a recognised tag. 

Yes, see https://github.com/Zverik/every_door/issues/880

> Even without a shop type, it adds value for someone searching for the shop via Nominatim, no?

https://www.openstreetmap.org/search?query=Kite.+Wing.+Sup.+Foil.&zoom=19&minlon=-0.8611607551574708&minlat=50.762450820167665&maxlon=-0.8569496870040895&maxlat=50.76409309678758#map=19/50.763272/-0.859055

> I don't remember! It was probably closed at the time I went past, or had sufficiently varied stock I couldn't decide. I can't even find it in a web search. 

but it was shop, right? then it would enable retag to shop=yes which would be still very unspecific but a bit better