So what to your mind is the distinguishing feature of a FAIRY ring?

This forum is read by many who do not recognise different species of fungi.
If your definition is that a Fairy ring is a ring comprising edible fairy ring champignons, how confident are you that someone who doesn't know fungi will be able to distinguish that from a ring of Clytocybe dealbata?

Are you saying that there is some other defining feature of a Fairy ring which will tell you that the fruiting bodies are of the Fairy ring champignon and not Clitocybe dealbata or other ring forming species?

It is dangerously misleading to give advice which, to the uninitiated, sounds like "if you have a ring of fungi on your lawn, the fungi are edible and delicious".