 Complete the following phrase:  Third kits traditionally started in European competition as a way of marking the occasion and existed in association football at least as early as the 1930s. Until 198990, the FA Cup competition rules stated: Where the colours of the two competing clubs are similar, both clubs must change unless alternative arrangements are mutually agreed by the competing clubs. Away kits were often similar as well, therefore third kits were worn in the 1948 FA Cup Final by Manchester United and the 