This might be applicable to any worldwide major sport, but I'm most familiar with how it pertains to the 4 North American major sports.
What does it mean when a player files their "retirement papers" with their respective league? I know in the NFL or MLB it starts the clock for when you can be considered for the Hall of Fame. But does that process categorize the athlete in other ways? I think I also heard that you have to go through some formal reinstatement process in order to play again (Brett Favre and Michael Jordan are good examples).
Does anyone know the terms of these retirement papers?