Instructions
Run the Jedi Knight 2 game.
Walk up to the player that you wish to send a private message to. Align the screen so that the player is in your crosshairs.
Press the "T" key and then press the "TAB" key to open the Jedi Knight 2 console.
Type "messagemode3" in the console, followed by the message that you wish to chat.
Press the Enter key. Only the targeted player receives your message.