Millwall have been fined £10,000 and told to "implement an action plan" after it was ruled some fans chanted racist language during an FA Cup game.
Supporters could be heard using a racist term derogatory to the Asian community in their fourth-round win over Everton in January.
The Football Association found the club had "failed to use all due diligence" and ensure its supporters refrained from using racist language.
Millwall will not be appealing.
However, the Championship club say while they accept there was a clear breach of the regulation they "fundamentally disagree with several elements which have shaped the subsequent sanction against them".
"Anyone found guilty of discrimination of any sort at The Den is not just issued with an immediate ban, but also offered the opportunity to attend Millwall For All's 'Fan Diversity Scheme', which aims to educate rather than simply just exclude," a club statement said.
"Education is key when it comes to dealing with people with unpalatable views and football clubs should be at the forefront of efforts to do so."
The chants followed crowd trouble near to The Den before the game started.
A man was slashed across the face during a brawl which the Metropolitan Police believed involved groups of rival fans.
Problems continued in the stadium with supporters invading the pitch and police separating the two sets of fans at full-time.
"The [independent regulatory] commission found that the club had failed to use all due diligence to ensure its responsibility was discharged under FA Rule E21 in respect of the charge against it for a breach of FA Rule E20," an FA spokesperson said.
"The FA investigated allegations of discriminatory behaviour and chanting after becoming aware of a video posted on social media.
"The FA subsequently alleged that the club failed to ensure 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 to race and/or ethnic origin and/or colour, during the fixture."