What is "class 4 light pollution" and could I estimate my own area's class visually? This question currently asks


  I am living in the northern hemisphere in Greece and in class 4 area (light pollution scale).Is it possible to see the Andromeda galaxy with a naked eye?


I'd never heard of a light pollution scale before. How does the scale work, and if I wanted to gauge or estimate my own area, can I do that by looking at objects in they sky visually?
Only the original poster can answer what was meant, but one system for rating the darkness of the night sky is the Bortle Scale. 

https://en.m.wikipedia.org/wiki/Bortle_scale