Purpose of the beanbag....

[Texas Aggie]

NCAA bean bags:

-- most fumbles (behind the LOS it isn't necessary unless near the OOB area)
-- illegal touches by kicking team
-- end of scrimmage kick
-- end of free kick if inside 5 and momentum takes into end zone
-- interception if inside 5 and momentum takes into end zone

There may be some more I'm not remembering right now. Back Judges usually carry 2 bags as they will often have both an illegal touch and end of kick. As an R, I rarely throw one.