I think for student athletes, the requirement is for the player to graduate from LSU and to have been named the national player of the year (Heisman, Naismith, etc.) to have a number retired. Shaq didn't have his retired until he officially graduated through correspondence classes. Not sure what the status on Semoine Augustus' jersey is though. And while no baseball player has worn #19 since Ben McDonald left, I don't know if it has been "officially" retired. GEAUX TIGERS
Pistol Pete never graduated and so cannot be in the LSU Hall of Fame, but there is no similar requirements to have a jersey retired. Basically each of LSU's five retired numbers are all members of the NCAA Hall of Fame or future members of such and also pro Hall of Famers or future ones. Shaq got his number retired after he had been in the NBA for a few years and had been named as one of the top-50 All-time NBA players (Maravich and Pettit were too). That assures him of a future NBA HOF spot. Only the five players above have had jerseys retired according to the LSU AD. Coaches sometimes "hold" an number for a while for various reasons.
don't want to question you since I don't know, but: Why is there 4 numbers hanging on the wall at the Box (15 Skip, 31 Wally, 19, McDonald, and don't remember 5 maybe)?