You don't need to create any prefs.
It uses the default prefs that badspot has in his server pref file.
It looks like this:
$Pref::Server::CurseFilter = 1;
$Pref::Server::CurseList = "stuff,forget,fuk,cunt,monday,starfish,friend, cigarette , suck my , richard ,";
$Pref::Server::ETardFilter = 1;
$Pref::Server::ETardList = " u , r , ur , wat , wut , wuts , wit , dat , loel , y ,";