MINT The cards must give the appearance of never having been handled, i.e. be in the condition in which they would have come from the printers. Imperfections in the printing process would not affect this (e.g. cards cut slightly off-centre, differences in intensity of ink, marks caused by defective printing plates).
EXCELLENT Cards have been handled but only to a minimum extent and with extreme care, allowing no blemishes.
VERY GOOD Cards completely clean back and front, with no damage. In particular corners would be untouched, but edges might show slight signs of wear.
GOOD Minor blemishes might be visible, due to handling or age, and there could be slight damage to corners. No creases or stains visible.
FAIR Showing signs of considerable handling and consequential corner or edge damage, or a card from one of the above categories with one defect, such as a crack, foxing, dirty mark.
POOR A card that is soiled, damaged or badly worn, or with a serious defect, such as back missing or badly cut down in size.