Unlike the Offline commands (see the code about Ghost mode, God mode, etc.) these commands actually work online and will give you a huge advantage. As usual, press 'T', 'ESC', and then quickly press the 'SPACE' key; this will bring up the command bar. Here you may type commands, and here are a list of great commands that many do not know about.
SetAutoAim 1: Auto Aim for mouse. SetAutoLock 1: A controller exclusive feature which locks onto your opponent and rarely misses him/her. Set Input {letter here} {Command here}: Set a command to activate (say I put God mode on the 'A' key, I press the 'A' key and the God mode command is activated). Feigndeath: Lay down and 'look dead' (This does not always work, but it's a good way to trick people). Open {Number here}: Sends you to a white box room or freezes. Open 128.121.19.232:(Server Address here)?Char=20: Spectator Mode. Open Door: Will show you a cool picture if you do it a few times. Set input a say|say|say|say|: Floods the screen allowing you to say more than one sentence in the touch of a button. (If you do the say|say|say| enough it will mess up and create FPS drop, this is known as the lag command) Set input a extra0: Auto Lock command that works with mouse. Ppp: Instant Freeze. Showall: Funny, just try it. fov{Number here}: It makes the graphics glitch or draw. Suicide: Commit Suicide(NOTE: If you use this in a TDM it will lower your teams' score!) Throwweapon: Throw away your weapon. Open 128.121.19.232:{Server Address here}?Char=10: Will let you change servers as a player instead of a spectator.
These all work online and most give you mad advantages(Auto Lock andd extra0) or are just cool to use(Showall, Spectator Codes!).