There is 4 factions that are listed in the units file
no faction (I call them Standard, in VSTrade)
Rlaan
Aera
Pirates
and then there is Planets, but I think they are always the same.
But I have a hard time finding out, what factions use what base set in:
http://vegastrike.sourceforge.net/wiki/Factions
Maybe someone could help me out and tell me exactly what base set each factions use (and sub factions, if different) . I would like to include the information in VSTrade, so people can easily select the right base type...