If I read everything correctly, you can have a folder longer than 3 inch blades in Los Angeles County, but they have to be concealed. Folders with anything up to a 3 inch blade may be openly carried, but anything longer than 3 inches must be concealed. Sounds pretty stupid, at least it did to me, and then I inquired about it in the Knife Laws forum and we figured out it actually is that way, IIRC. Check out the Knife Laws forum and look for my thread, it's kind of old.