Overall it's urban dictionary but I edited some bits:
1- Monster can't look at them or they'll burn your eyes out.
2- Heinous, Busted- Needs plastic surgery.
3- Plain Ugly- Someone who was born ugly.
4- Below Average/Unattractive- Someone you'd never go out with.
5-Average, could be slightly unnatractive, someone you wouldn't look at twice.
6- Barely Do-able, wouldn't date them, but they can look OK if they try hard, also wouldn't look twice.
7- Cute- someone you wouldn't be ashamed of, I could settle for this but at the same time I would be thinking I could do better.
8-Generally Hot/Good Looking- definitely datable.
9-Super Smoking Hot- People you don't see in public often and most likely out, of my league
10- Perfection- dosen't exist but someone can and definitely out of my league
IMO the 1-10 scale will only apply to you/yourself. e.g. If I saw a guy and thought he was really hot I would give him a 10 because he is exactly my type. But in reality he's probably only an 8, he could never be a model he's attractive to most or many but not to everyone.
Another point it how attractive the person rating actually is, you can't expect a 2 to rate anyone above 5 because to them everyone above that would probably be attractive. In the same way you can't get a 10 to rate anything below 6 because they would probably think anything below that is ugly.
People say they would go no lower than a 7, but could a 7 to you be a 6 to me?