PlayStation Knowledge Center
Inside the package for LittleBigPlanet for PS Vita, there is a voucher that states it is the pre-order bonus for the Big Daddy, Little Sister, and Knights of Old costume pack DLC. This is a misprint and the voucher is actually the online pass for LittleBigPlanet for PS Vita. The code on the voucher is a valid online pass code, however, the graphics on the voucher itself is misprinted.
The vouchers are live so you may go ahead and redeem it to receive the Online Pass for LittleBigPlanet.
If you pre-ordered LittleBigPlanet for PS Vita, you should have received the voucher for the costume DLC from your retailer. You can go ahead and use that voucher to claim the DLC content. We apologize for any confusion.