Abstract: A key and insert assembly is designed for the identification of keys or key blanks. The key is provided with a slot through the key head which is oriented in a plane parallel with the face of the key head. A window through the key head intersects the slot. The slot is designed to receive a thin insert made of synthetic resin and the window area allows a portion of the insert to be displayed. Information regarding the key or other codes may be printed on the insert region which is displayed. In a preferred embodiment, the insert is retained in the slot by a snap-fit arrangement.