FIFA World Cup jerseys are important to participating FIFA World Cup teams, fans, sponsors and producers alike. A well-designed team jersey has to be comfortable for players to wear during matches, but also has to stand out and make both players and fans proud to wear it. Jerseys of national teams, with the names of the favorite players are best-selling sports apparel all over the world. Because of this, and as protection of their intellectual property, shirt designs are shrouded with secrecy until their revelation.

Notable designers include:

• Nike: United States, The Netherlands, Slovenia, South Korea
• Adidas: Denmark, Spain, South Africa
• Puma: Switzerland, Uruguay, Italy
• Umbro: Sweden
• Joma: Honduras

The 2010 Nike jerseys were all made of recycled discarded plastic bottles. In order to create the Nike jerseys, Nike’s fabric suppliers sourced discarded plastic bottles from Japanese and Taiwanese locations, melting them to create new yarn which was used in the fabric for the jerseys. Each jersey was created using eight discarded bottles.http://www.notcot.com/archives/2010/03/nike_jersey_in_a_plastic_bottl.php

FIFA has enforced strict regulations regarding tenues to be used during the World Cup. Main points from these regulations are:

• Players and officials are not allowed to display any kind of political, religious, commercial or personal messages in any language or form on their playing or team kits, equipment. FIFA explicitly prohibits taking off one's shirt to celebrate a scored goal, whether revealing a personal message, or not. Referees are instructed to fine this action with a yellow card.
• Each team informs FIFA of two team kits, one predominantly black, one predominantly white. One kit is defined as the official kit, one is defined as the reserve kit. A kit consists of a shirt, shorts and socks. Goal keepers have to be provided with three contrasting colored kits. Additional gear, including gloves, caps, wristbands, hairbands, etc also have to be approved by FIFA. Shoes are not part of the official team kit.
• As far as possible, each team wears their official team color kit. If the team and referee colors may cause a mix-up, the 'home' team is entitled to wear their official team kit. Each team is entitled to wear its official team kit at least once during the tournament.
• Each team player is assigned a unique number. This number and popular (abbreviated) name has to feature in contrasting color on his shirt. The allotted numbers remain during the entire tournament.
• Each team player will wear a sleeve badge with official competition logo on their right arm.http://www.fifa.com/mm/document/tournament/competition/56/42/69/fifa_wc_south_africa_2010_regulations_en_14123.pdf

2004 Cameroon one-piece jersey incident
In 2004, Cameroon played during the African Cup of Nations wearing a one-piece kit, designed by Puma. FIFA objected to the kit, warning Cameroon the one-piece kit was in violation of FIFA regulations, which describe the official soccer kit was required to consist of two pieces, a shirt and shorts. Despite the warning, Cameroon played their African Cup group stage matches wearing the on-piece kit, which was condoned by FIFA. However, FIFA demanded replacement of the one-piece kit after the group stage. Cameroon failed to comply, and played their quarter-final match wearing the same one-piece kits. FIFA disciplined Cameroon with a monetary fine and a six-point deduction for the 2006 FIFA World Cup Germany qualifiers. The issue lead to a clash between FIFA and manufacturer Puma, which was later resolved out of court. The details of the agreement weren't disclosed. http://www.fifa.com/aboutfifa/federation/administration/releases/newsid=92356.html http://www.footballshirtculture.com/2006101475/history/the-cameroon-2004-one-piece-kit-story.html

2002 Cameroon sleeveless shirt incident
The 2004 incident was not the first time Cameroon used a controversial shirt. In 2002, Cameroon played using a sleeveless shirt. While regulations do not explicitly prohibit sleeveless shirts, the regulations state a sleeve badge needs to be worn over the sleeve. The issue was resolved by using black sleeves, which remained the impression of a sleeveless shirt.http://www.footballshirtculture.com/2006101475/history/the-cameroon-2004-one-piece-kit-story.html