ScreeIn the pipe 5 by 5Reviews:
Mount Laurel, NJ
Seems it has to do with the Wi-Fi Protected Setup stuff. From some site that reviewed the DIR-655...
"The DIR-655 also appears to support Wi-Fi Protected Setup. This standard from the Wi-Fi Alliance simplifies setting up a secure wireless network. There are two mandatory methods required for WPS products: Push-Button Configuration (PBC) and Personal Identification Number (PIN). A close inspection of the DIR-655s case reveals a black push button embedded in the black trim on the right side of the case. Additionally, theres a menu entry in the DIR-655s Web interface labeled Wi-Fi Protected Setup. However, neither the instruction manual for the DIR-655 router nor the DWA-652 client card made any mention of Wi-Fi Protected Setup. For now, I have to conclude that the DIR-655 is Wi-Fi Protected Setup capable, but new drivers for the client card will have to be released before youll see the benefits."