Do me a favor, check your gamecube game boxes

Do any of your games have a small notch of plastic missing on the right hand side of the bottom of the box? I noticed that both ED and SMS have this, but no other games do? What's the purpose? I don't think nintendo could be saving more than 1.50$ on plastic for the entire production run of a game by taking out the extra gram or two of material there. Surely there must be some reason for this?