Grade A is basically pristine with all labels and packaging included. They'll pick you up on anything. I wanted to return a pair of Fidelio headphones to Amazon FR but after being stuck at customs - and subsequently returned to me again - Amazon refunded me and told me I could keep them. I sold them to CEX and they tried to get me down to B grade due to some lint on the felt pads. The headphones had barely left the sodding box, maybe for two minutes, had no marks and the box was like new. Yes if a plug is scratched and they notice, it will be B.