This goes for all Quake games so if you have the answer give it, also, make sure you list what game the command is for:

What's the command to turn on/off the HUD
on/off weapon
Right/Left/Center weapon
FoV command
Crosshair on/off

Quake 1 had a config file called Quake.rc, did every other Quake game have this file and if so what did they name it? For example any game on the GS/Source engine use Valve.rc