That said...I don't even see schools mentioned in the prohibited places list...
(16) Prohibited activity. (a) Except as provided in par. (b), neither a licensee nor an out-of-state licensee may knowingly carry a concealed weapon, a weapon that is not concealed, or a firearm that is not a weapon in any of the following places:
1. Any portion of a building that is a police station, sheriff's office, state patrol station, or the office of a division of criminal investigation special agent of the department.
2. Any portion of a building that is a prison, jail, house of correction, or secured correctional facility.
3. The facility established under s. 46.055.
4. The center established under s. 46.056.
5. Any secured unit or secured portion of a mental health institute under s. 51.05, including a facility designated as the Maximum Security Facility at Mendota Mental Health Institute.
6. Any portion of a building that is a county, state, or federal courthouse.
7. Any portion of a building that is a municipal courtroom if court is in session.
8. A place beyond a security checkpoint in an airport.
(b) The prohibitions under par. (a) do not apply to any of the following:
1. A weapon in a vehicle driven or parked in a parking facility located in a building that is used as, or any portion of which is used as, a location under par. (a).
2. A weapon in a courthouse or courtroom if a judge who is a licensee is carrying the weapon or if another licensee or out-of-state licensee, whom a judge has permitted in writing to carry a weapon, is carrying the weapon.
3. A weapon in a courthouse or courtroom if a district attorney, or an assistant district attorney, who is a licensee is carrying the weapon.
(4) Training requirements. (a) The proof of training requirement under sub. (7) (e) may be met by any of the following:
1. A copy of a document, or an affidavit from an instructor or organization that conducted the course or program, that indicates the individual completed any of the following:
a. The hunter education program established under s. 29.591 or a substantially similar program that is established by another state, country, or province and that is recognized by the department of natural resources.
b. A firearms safety or training course that is conducted by a national or state organization that certifies firearms instructors.
c. A firearms safety or training course that is available to the public and is offered by a law enforcement agency or, if the course is taught by an instructor who is certified by a national or state organization that certifies firearms instructors or by the department, by a technical college, a college or a university, a private or public institution or organization, or a firearms training school.
d. A firearms safety or training course that is offered to law enforcement officers or to owners and employees of licensed private detective and security agencies.
e. A firearms safety or training course that is conducted by a firearms instructor who is certified by a national or state organization that certifies firearms instructors or who is certified by the department.
2. Documentation that the individual completed military, law enforcement, or security training that gave the individual experience with firearms that is substantially equivalent to a course or program under subd. 1.
3. A current or expired license, or a photocopy of a current or expired license, that the individual holds or has held that indicates that the individual is licensed or has been licensed to carry a firearm in this state or in another state or in a county or municipality of this state or of another state unless the license has been revoked for cause.
4. Documentation of completion of small arms training while serving in the U.S. armed forces, reserves, or national guard as demonstrated by an honorable discharge or general discharge under honorable conditions or a certificate of completion of basic training with a service record of successful completion of small arms training and certification.