I don't think anything is a certainty with our current legal system.
I recall a few years back some guy had been doing some flooring work in Seattle. He took a break, stuffed the curved blade linoleum knife in his back pocket, and took a walk.
He was arrested by Seattle police for carrying a concealed weapon. No other reason, just saw part of the knife extending out of his rear pocket. The difference here is this is a "Fixed Blade knife", but give me a break.
In the past our carry permits have gone by the title of CWP "Concealed Weapons Permits" or CCW "Carry Concealed Weapon". They are now called "Carry Concealed Pistol" to deny any other concealed weapons carry.
For the most part you will be fine with a knife clipped in your pocket. Just don't quote me on it if you get arrested.
In the state of Washington a pocket knife is not considered a weapon and is legal for an adult to carry on school grounds. I called the school district to verify this. They said they would have me arrested. I asked them to quote me the law or even school policy that denies pocket knife carry to an adult and they cannot, and do not care. Next, I called the PD. They said I could be arrested. Again I asked for the law that covers this. They had none and did not seem to care. I then quoted WA state code to them, and the reply was "well, there you have it". Very flippant and arrogant. I called the city District Attorneys office for clarification. They had no clue and said they would get back to me with more info. Never heard from them again.
I am quite confident the law is on my side. I am also quite confident they would try to confiscate my knife or have me arrested if they saw one in my possession.
We have too many laws in this country, and much of the enforcement of these prolific laws is vague at best. I think the old Ignorance of the law is no excuse is BS now. It works well in a common law environment where it is known, Dont steal, dont kill, dont assault etc. When you screwed up you knew it. Everyone else knew it as well. You dont need a freaking law degree to know you have done wrong. Our system is no longer based on right or wrong, but legal or illegal. Im sure some of us unknowingly break a dozen or more laws of some kind each day without even knowing it. Thankfully we are not a police state yet, so enforcement of these foul-ups is sporadic at best. I am really starting to miss Thomas Jefferson as president. (End of rant).
TR (continuing to carry clipped knives in defiance of Da Man)