For those of you that have not figured it out yet (because you live in the United States), a "kit" is a sports uniform for soccer. In association football, kit (also referred to as strip or soccer uniform) is the standard equipment and attire worn by players.
Football kit has evolved significantly since the early days of the sport when players typically wore thick cotton shirts, knickerbockers and heavy rigid leather boots. In the twentieth century, boots became lighter and softer, shorts were worn at a shorter length, and advances in clothing manufacture and printing allowed shirts to be made in lighter synthetic fibres with increasingly colourful and complex designs. With the rise of advertising in the 20th century, sponsors' logos began to appear on shirts, and replica strips were made available for fans to purchase, generating significant amounts of revenue for clubs.
The Worst Kit Designs Ever infographic has been provided to Apparel Search by Samantha at http://www.stand-out.net/.