Yeah, the WoW card game includes special "loot" cards that have little scratch-off bars on them. When you get one of these rare cards and you scratch the bar off, you get a unique code that you use to redeem in Booty Bay. Once that code is used to redeem your loot, that code is used up and it cannot be used by anyone else.
For details go this link http://www.ssegames.com/News116.htm I googled, there’r more loot items there.