I got that same designation (unless the list of cards was somehow jumbled, which I doubt):
N0: AUTHENTIC 1965 Topps 350 Mickey Mantle Card
I just wanted to get it slabbed for the day I decide to sell it. Figured it would get a low grade g or vg or something, but now I'm perplexed. Here's a quick scan of it. The back is free of problems...