Guys, need help... can anyone tell me about the condition code?

what does C1 meant?
an so on till C10...

coz i found C9 TFTM... thinking of buying...

what should i expect? or shouldn't i buy it?

so it so subjective...

i can say mine is in C10 but u would say it in only C7...

should it be a spec on how it been valued..

for example.. C10 is for sure flawless...
C9-only packaging damage...or whatever...

so..is the any standard that had been made?