Some will work other will not.
Information Commands
Stat FPS - Toggles the display of your framerate
Stat Net - Toggles the display of network statistics including Ping
Stat Audio - Toggles information about the audio system
Stat Engine - Toggles information about the rendering system
Stat Game - Toggles information about the game engine
Cheat / Fun Commands (SP only)
Behindview - Toggles between 1st and 3rd person view
God - Makes your character indestructible, toggles on or off
Fly - Allows your character to fly
Ghost - Allows your character to fly and move through solid objects
Walk - Switches off Fly and Ghost modes
Allweapons - Gives you all weapons
Allammo - Gives you maximum ammo for all your weapons
Loaded - Gives a combination of all weapons and all ammo
Playersonly - Freezes all bots
Addbots [number] - Adds the specified number of bots to the current game
Killbots - Kills all bots in the game
General Commands
Say [text] - Shows specified text in global chat
Teamsay [text] - Shows specified text in team chat
FOV [degrees] - Changes the Field of View to the specified degrees
Slomo [speed] - Alters the speed of the game to the value specified. Values above 1 speed up the game, values below 1 slow it down
Showhud - Toggles whether to display or hide the HUD
Togglescreenshotmode - Toggles 'screenshot mode' which removes all text, the HUD and your gun
Setbind [Key,Command] - Binds the specified command to the specified key
Setsensitivity [value] - Changes your mouse sensitivity to the specified value
Shot - Takes a screenshot in .BMP format
Brightness [value] - Changes the brightness to the specified value
Contrast [value] - Changes the contrast to the specified value
Gamma [value] - Changes the gamma to the specified value
Demorec [demoname] - Starts recording an in-game demo with the name specified
Demostop - Stops recording a demo
Demoplay [demoname] - Plays back a demo with the name specified
Switchlevel [mapname] - Changes the level to the map specified
Switchteam - Toggles you to the other team
Suicide - Kills your character
Open [mapname or IP] - Loads up the specified map, or joins the specified IP address
Reconnect - Reconnects to the last connected server
Disconnect - Disconnects from current server
Exit, Quit - Exits the game to desktop immediately
Not sure if general commands work in SP haven't tried.
In the ROengine.ini go down to [Engine.ISVHacks] and turn these from false to true if they don't work in default.