I'm not sure what that is, but I don't think that's what it is. There is a website on each box that asks you to go to, and ( you have to set up an account of course ) and you put in the code for credits. You then can turn in credits, like My Coke Rewards does, and 'purchase' items. Though, I think these codes give you 100 credits / points each as opposed to MCR's average 3 each. ( Two more codes being put up for Auction this afternoon )
The monster u codes are a current promotion that gives music downloads on the boxes, they come on the newer cereal boxes and normally look like this: http://www.listia.com/auction/10181789-disney-pixar-kellogs-codes-for-monsters
They have been going for a lot more points than the regular codes lately so if you have any people will usually pay more. : ) Good luck!