I live in Dayton, and Im wondering the same thing. From what I can tell, the state policy is to leave discretion to the local authorities. I know cities all seem to have their own ideas on what you can and can't carry, and the definition of "open" and "concealed" varies locally too. For example, in Beavercreek and Fairborn (suburbs), I think its open carry provided you can see and identify the knife. If that means a handle in your pocket, then that is considered open carry. Most municipalities have some type of restriction on blade length for concealed folders and fixed blades. I think its 3 inches for fixed where I live. In rural areas, where Im from originally, it seems like you can carry anything short of a sword, and a machete is seasonally allowed. I have a friend in Cincinnati who started carrying a 5" fixed when he moved to OTR. He looked up the legal restrictions of the city and UC, where he attends school, before hand and bought something that he couldnt be arrested for. He is military, not sure if he's given special treatment for that. Im not sure on these laws, but I carry fixed blades and this is my experience with police. If anyone has any solid laws it would be great to know.