The hairy part is for "Gun Free Zones" and they are all somewhat different. For example, a k-12 is the most problematic. But on a Florida University, with a ccw license, the possession of a pistol is a misdemeanor. However, that would require me to exit retrieve and re-enter the building. That can also be problematic. It means I have either left students etc. behind, or I have already brought them out when I exited.