You really need to know your local laws. I know that here in California that it is ILLEGAL to carry knives of a certain size anywhere on public school property. And by ILLEGAL, I don't mean just a school policy, I mean you can be arrested and charged in criminal court. And in court, it won't matter one bit how YOU define your knife. If a knife is illegal due to it's size or design, it WILL be regarded as a weapon by the prosecutor.
When I go to my kids school I leave my fixed-blade locked in the car. I carry a legal folder in my pocket.
And if anyone thinks "Who's gonna know if I have a knife on school grounds?", well, is there any chance that you might pull it out to cut something, maybe out of habit? Is there any chance that it could be seen by others? Is it possible that it could fall out of your pocket, like maybe if you were pulling something else out of your pocket? We all know about how school personnel can overreact (zero tolerance, etc), so don't be surprised if a school employee calls the cops on you if they see you carrying, on school grounds, what THEY consider to be a "deadly weapon".
I openly carry a fixed-blade wherever it is legal to do so. I have never seen any "NO WEAPONS" signs at any business here in San Diego. And if I did, I would ignore them. Of course, due to the fact that the owners of private property, and there representatives, have the right to insist that a person leave their property for any reason, and call the cops and have that person charged with trespassing if they don't leave, I would leave if asked to do so and take my money elsewhere. But in all the years I have been carrying a fixed-blade, I have never been asked to leave or put my knife "away".