Newcastle United has asked supporters to refrain from wearing traditional Arabic clothing or Middle East-inspired head coverings at matches, if "they would not ordinarily wear such attire".
Since the club was taken over by Saudi Arabia's Public Investment Fund (PIF), fans have been spotted in and around St James' Park wearing costumes emulating traditional Middle Eastern headdresses known as keffiyeh.
Some have also donned long robes.
Now, the club is requesting that fans refrain from participating in the trend.
They say dressing this way could be perceived as "culturally inappropriate" but stressed the new ownership is not offended.
"No-one among the new ownership group was in any way offended by the attire of the fans who chose to celebrate in this way," said the club in a statement.
The club also emphasised that the request only applies to those wearing costumes, not to people who dress in the attire for cultural reasons:
"All visitors to the club are, as always, encouraged to wear whatever is the norm for their own culture or religion, continuing to reflect the broad and rich multicultural communities and groups from which the club proudly draws its support."