Mac Pro comes with useless USB extension cable?

Can anyone explain this? This little raised groove prevents any USB device from plugging into it. What the..?

see photo:
http://img528.imageshack.us/img528/7711/wtfusbtf5.jpg

From the Apple website, it says USB keyboard extension cable, so I assume it is only for the included USB keyboard? I don't see Apple saying it includes a universal USB extension cable.

Ahhhh.. for the keyboard only. Interesting choice...sorta.

Apple's keyboards are basically made to fit the iMac in cable length, or to put it differently, they want your computer to be on the desk. If you choose to keep the tower under the desk (yech), you can use that cord.