(2)(a) A person shall not possess any firearm, electric weapon or device, destructive device, or other weapon as defined in s. 790.001(13), including a razor blade or box cutter, except as authorized in support of school-sanctioned activities, at a school-sponsored event or on the property of any school, school bus, or school bus stop; however, a person may carry a firearm
1. In a case to a firearms program, class or function which has been approved in advance by the principal or chief administrative officer of the school as a program or class to which firearms could be carried;
2. In a case to a career center having a firearms training range; or
3. In a vehicle pursuant to s. 790.25(5); except that school districts may adopt written and published policies that waive the exception in this subparagraph for purposes of student and campus parking privileges.
For the purposes of this section, "school" means any preschool, elementary school, middle school, junior high school, secondary school, career center, or postsecondary school, whether public or nonpublic.