Doom 3 Easter Egg - Reference to Id Game Quake

First you need to play level Communication center. You will get PDA somewhere. I cant remember whose PDA it is. Anyway read messages on it. One of them is sent from the PDA owner's son who is saying:``The games you sent to me were awesome! The new Quake 43 is even better than super turbo turkey puncher." Quake is game done by ID software, which created Doom.