Here they are:
-windowtitle obvious use is obvious.
-windowtitle "CombatArms" -rez Engine.REZ -rez Game -authip 126.96.36.199 -authport 10001 -pcroom 0 -Ver VER_EU_2.1105.01 -UserId
-rez unsure, change word texture?
-authip change login server
-authport change login server port
-pcroom unsure, debugging settings?
-Ver client version, not server side checked (so you can change it/possibly play with an older version of engine.exe) EDIT, it's checked
Come to think of it, does anybody have the server ip of the NA servers, (just start the game and do a netstat) maybe I can play on the NA servers (and vise versa) too.
And these will obviously not work for NA with the current parameters (you'll need to change the -authip parameter for it to work, and the -VER parameter too), ver can be found in the debug messages. And the ip can be found with netstat