Novert
From OdaWiki
novert
0: Disables novert.
1: Enables novert.
This variable prevents Odamex from processing any mouse movements going up or down. By default, Odamex interperts mouse movements up and down as moving forwards and backwards, however this is slightly disorienting to some players, thus novert allows players to effectively disable this undesirable behavior. The variable is named after the mouse driver of the same name.