Aye, S7 is only the second site I've used that features intermediary ratings. Between dA, which is arguably too lax, and Buzzly.art, where certain early staff became notorious for persecuting clerical errors with maximum prejudice, my compass for "common sense" was totally scrambled. :P I follow a rule of thumb erring to caution and I've still tripped up in my own gallery, so no worries on mistakes: misratings only become problematic if they look to be deliberately flouting the rules.