Numbering in sports - Topics

Why do some athletes choose a number that means something off the field? How do motor racing numbers get chosen and defended? Memorial matches and shirt retirements after a player's death Why is the number 10 so loaded in football? Why do football fans sing about a number instead of a name? How does a league handle a number when a player dies mid-season? What happens when two players want the same number? Do college athletes wear different numbers from professionals? What does retiring a jersey number actually retire? Why did football assign shirt numbers by position and when did that stop? Who owns a squad number when a player leaves the club? Why did basketball allow 0 and 00 but not every combination? How do position codes and scorekeeping use numbers differently from jerseys? Kit numbers and the unwritten hierarchy in a squad Why do rugby shirts still follow position numbering while football shirts do not? Why do fans buy jerseys with someone else's number on the back? How are bib numbers and race numbers allotted to athletes?