A football club fears the granting of a trademark for a popular acronym used by its fans could force them to abandon it or face legal action.
Sheffield Wednesday fans regularly use 'WAWAW', which stands for "We're All Wednesday Aren't We", on social media.
However, the Sheffield Star reports 'WAWAW' was registered as a trademark by Paul Jennings in 2018.
It means Mr Jennings could take action against anyone using it without his consent.
The Championship club has appealed to the government's Intellectual Property Office (IPO) to try and overturn the trademark.
Mr Jennings, from Sheffield, is a fan of the club who purchased a box last season, according to his solicitor.
Emma Ward, from Nelsons Solicitors, confirmed her client was the registered proprietor of a UK trademark for WAWAW.
The club said it was "disappointed" by Mr Jennings' actions.
"We can confirm we have challenged Mr Jennings' trademark as 'WAWAW' has, without question, grown organically from within the Sheffield Wednesday family for many years," it said in a statement.
"We are confident the decision of the Intellectual Property Office will take this overwhelming factor into consideration and result in our challenge being successful."
It added it had not been informed of Mr Jennings' application and would have challenged it if it had.
The Sheffield Wednesday Supporters' Club said it "fully supports" the club's actions.
Ms Ward said: "The trademark was registered in accordance with trademark law; the application for registration was not opposed by Sheffield Wednesday or anybody else.
"As Sheffield Wednesday have applied to cancel our client's trademark at the Intellectual Property Office, it would not be appropriate to comment further at this time, as proceedings are ongoing."
The IPO said it would not comment until the case had been resolved.