Stevenage have been fined £5,000 after admitting a Football Association charge of sexist chanting towards a female official during a home game in March.
About 75-100 home fans chanted for several minutes as fourth official Lisa Rashid replaced an assistant referee midway through their match with Bury.
The League Two game had been chosen as Stevenage's women in football day.
"We will impose significant bans on any supporters found guilty of such behaviour," said chairman Phil Wallace.
"Financial penalties really hurt small clubs like ourselves and this is a real blow to us as we fight financially to build a winning team."
Stevenage breached Football Association rule E20, which states "the club had failed to ensure that its spectators, and all persons purporting to be its supporters or followers, conducted themselves in an orderly fashion and refrained from using abusive and/or insulting words which included a reference, whether express or implied to gender, whilst attending a match in which it was involved".
The Hertfordshire club have also been ordered to implement a 15-point action plan - though the FA concluded they were not at fault for the behaviour, or the way it was dealt with on the day.
The FA say the chanting against Rashid - who assumed assistant refereeing duties around the 18th minute of the game - was "extremely offensive, both blatantly sexist and in vulgar indecent language".