The Old Trafford club has sent a text message to all fans attending the match at Anfield this weekend, by means of deterring a repeat of the abuse suffered by City's Raheem Sterling at Stamford Bridge last week.
Since the ugly scenes that transpired last weekend, which are now subject to a Police investigation, Premier League clubs have reissued a warning to fans about their behaviour at future fixtures.
United head to Anfield to face arch-rivals Liverpool on Sunday, with 16 points separating the sides in the league standings.
Previos games between the two clubs have been marred by vitriolic chanting that has referenced the Munich air disaster and the Hillsborough and Heysel tragedies.
Therefore United has urged its supporters to refrain from such behaviour when they make the short trip to Merseyside on Sunday.
The text sent to fans read as follows: 'Any kind of racist or discriminatory chanting or behaviour is unacceptable and has no place in the game, and also songs that reference tragic events that have affected other clubs.'