Mint - Only action seen is sorting.
Near Mint - Possibly played and edge faces may be yellowed.
Good - Have been handled often and no longer as smooth.
Played - Non-uniform bends.
H. Played - Defaced and/or rough patches.
Poor - Opponent can identify card.

Cards may have uniform curvature. This is natural aging and is most often harmless. Easily rectified by placing the card under a heavy item for an extended time.