The origin for the tradition is unknown; however, one possible explanation came that Cardiff City after winning the 1927 FA Cup Final adopted triangular corner flags to commemorate the victory as well as reminding their South Wales derby rivals Swansea City of this. From then on, it became an accepted tradition that only winners of the FA Cup would be entitled to use triangular corner flags. This theory was popularised in the 1997 film "Twin Town". While a number of FA Cup-winning clubs including Arsenal and Aston Villa do use triangular corner flags, some such as Liverpool do not. Some clubs that have never won the FA Cup use triangular corner flags, such as AFC Wimbledon, though they view themselves as the successors of Wimbledon who did.