Q: Can *private* universities in Florida set their own policy regarding firearms possession, storage, concealed carry, etc?

A: Generally, private property owners can regulate activity on the premises of their property. Because vehicles are the most common mode of transportation for individuals and the right to carry a firearm in a vehicle while "securely encased," the exception to this general provision (private property owners' right to prohibit possession of firearms) is in the "guns-at-work" statute, section 790.251, Florida Statutes prohibiting a landowner/employer from restricting the "securely encased firearm in a vehicle" rights of employees, and includes customers and invitees.

More specifically, and individual may voluntarily waive a constitutional right such as the right to keep and bear arms such as when entering a store with signs prohibiting entry with a firearm, or one can consent to be firearm free and to be searched for firearms by authorities designated to enforce the consent, such as in public buildings like the courthouse.

A private university which accepts students and faculty on its campus may require the student or faculty member to waive rights. Students Fourth Amendment rights against searches and seizures in dorm rooms are commonly waived. If the private university requires a written waiver by students or invitees on their property, then the waiver would generally be valid. The difficulty comes from the UNF case which preserves a person's right to possess a securely encased firearm in their vehicle if a customer, employee, or invitee. But that UNF case was based upon the public univerity's lack of ruelmaking authority as a public university, and there wasn't a voluntary waiver.

I think a private property owner could still restrict the possession of a firearm even in a vehicle with a voluntary waiver in exchange for using the property. Then there is an voluntary exchange not based upon any governmental authority. The constitution is not at issue.