• The NFL has strict guidelines when it comes to players' jerseys.football huddle image by sparkia from Fotolia.com
  
  Jerseys worn by players in the NFL have been regulated by rules that were established in 1973. These rules set guidelines for what numbers can be worn by players at each position. Over the years, the NFL has adapted its rules---but only slightly---on jerseys to fit the advances of technology and the growth of media coverage.
  
  

Positions

• Under the NFL rulebook's Rule 5, Section 3, Article 3c, players at each position are limited to certain jersey numbers. Quarterbacks, punters and kickers can wear numbers 1-19; running backs and defensive backs 20-49; centers 50-59 (60-69 if one in the 50s is not available); defensive linemen, guards and tackles 60-79 (defensive linemen 90-99 if 60-79 are not available); linebackers 50-59 (90-99 if one in the 50s is not available); and tight ends and receivers 80-89. In 2004, NFL owners voted to allow receivers to wear numbers 10-19.
  
  

Numeral Size

• Jersey numbers---which must be on the front and back of the jersey---must be at least eight inches tall and four inches wide. Smaller numbers must also appear on the upper arm or shoulder. These smaller numbers are also known as "TV numbers," which enable TV broadcasters to identify the players more easily. Jersey numbers also can appear on the sides and back of a player's helmet but are not mandatory.
  
  

Exceptions

• All exceptions to the NFL jersey numbering rules must be filed with the league commissioner's office. A recent high-profile instance of this was New Orleans running back Reggie Bush. Bush requested to be allowed to wear No. 5, which he wore in college. His request was denied, and the team assigned him No. 25.
  
  

Retired Numbers

• Most teams in the NFL have retired some numbers of great players. Jerseys that have been retired are not issued to any current or future players of that team. NFL guidelines require the team to use a retired number if there are not sufficient numbers available to meet the league's rules on jersey issuance.
  
  

Official Supplier

• As of 2010, Reebok is the official manufacturer of NFL jerseys. The licensing agreement between Reebok and the NFL took effect in 2002. The agreement gave Reebok exclusive license to manufacture, sell and market NFL merchandise, including game jerseys, sideline apparel, practice apparel and footwear.