I believe that is a city ordinance here in L-town. Some states make the reasonable asumption that if a person can pass the legal requirements to carry a gun, they can also be trusted with a back-up knife. Oklahoma should follow that lead.Personally, I would LOVE to see some changes made! Oklahoma knife laws are way too ambiguous to begin with!
Where in the books does it state that if the blade is longer than the officers palm you're either going to jail or at a minimum risking confiscation? Nowhere, that's where. But I have had more than one local LEO tell me that, believe it or not.