Most years, there are a few college players who either are not eligible in time for the NFL draft, or due to academic or disciplinary reasons are not able to return to their college team. Instead of sitting out a year, they make themselves available to the NFL. Sometime during the summer, the NFL holds the supplemental draft. The current draft order is used, and teams bid on players they want by round. So if someone wants to draft Paul Oliver, they would submit "Paul Oliver, 2nd round" if they were willing to spend a 2nd round pick on him. The team who bids the lowest round, and is in the lowest draft spot, gets the player, but has to forfeit the corresponding pick in the next year's draft.