The dumbest rule that fortunately was only "tried" to be enforced was no gun racks in the student vehicles in the parking lot. This is was a rural area where for almost a hundred years people would have guns in the gun-racks in their trucks mostly. But with fire arm thefts etc it was pretty rare to actually have a gun loaded or unloaded in the gun-rack. Generally you'd just have the gun in the rack if you were hunting, or patrolling your ranch or whatever.

Then Columbine happened and suddenly gun-racks and leather trench coats, aka dusters, another extremely common piece of clothing in a rural ranching town were priority number one by reactionary's. Hundreds of otherwise lawful students were suspended, ticketed, arrested etc and finally after several months I assume someone had a "are we the baddies?" moment, and coupled with hundreds of lawsuits, the school system got a new superintendent and suddenly gun racks and dusters were back to being treated as the mundane items they are.

Not a rule, but some stupid thing that was allowed to slip by for way too long.

My highschool's firewall would often block the most innocuous websites, but that somehow did not include Pornhub. While they did eventually add it in, by that point it had been a known thing for years with even multiple cases of students going on it during classes.

No bottle flips.

I made up a monster called dogger that lived at the end of the field in my primary school.

His arms and legs were made of rats if I recall correctly.

Ross got so upset that we were banned from saying that word.

We had very few rules in high school until a new principal came in during my senior year. We didn't even have attendance, as the school believed that it was the students' responsibility to succeed and graduate (it was a laboratory school, basically part of a college, so it was weird. It was K-12, and I graduated in a class of 25.).

This new principal comes in and lays down new rule after new rule, most were either ignored or caused enough uproar from tenured faculty and parents that he caved. For some reason, one day, he walks through the hallway and cleans out all the lockers, as well as picking up the unattended backpacks left on the floor. He takes ALL schoolbooks, notebooks, supplies, and electronics. Amazingly, he left some lockers alone, deaming them organized enough to satisfy him. They all belonged to his daughter and her friend group.

Then he takes all this stuff into his office, and proceeds to charge students $50 each to get school issued books back. He keeps all other supplies and electronics, announcing that he will have a sale at the end of the year to raise money for school athletics (which, being an extension of the college, had shitloads of cash to play with).

The University Police department showed up and were ready to arrest him for theft. It took nearly a week to redistribute everything, and he ended up in front of a local judge who was the father of a student.

Then he abruptly ended music, theatre, art, and home econ. classes by locking the rooms and firing the staff by posting signs that these were a waste and unnecessary strain on the school budget. All of the teachers were tenured through, and the classes and programs paid for by a combination of parent donations and a hefty amount of money from the university, which is well known for its communications, theatre, teaching college, and school of music (these are the programs that sell the university nationwide).

At the end of the year, during commencement, the University president made a speech that basically dressed down the principal publically, and then he announced that the principal was not taking part in the ceremony, and should go home as he would not be returning next term. The principal was in his robes, sitting on the stage, and waiting to hand out diplomas while this happened. The entire gathering of parents and students cheered.

And that's how a principal who thought he was going to be adored for "cleaning up" a school for the gifted like he was trying to run a drug riddled, inner city, school in the middle of Chicago, instead of school basically run by the students in a mid-sized University town surrounded by corn fields in Indiana.