cpk, you are correct. Carrying a double edged folding knife is legal as long as you carry it in the closed position. The statute specifies that a "non-locking folding knife" or a "folding knife" do not qualify as a dirk or dagger. According to the CA Penal Code, a dirk or dagger is any instrument capable of ready use as a stabbing weapon, so if you carried your double edged folding knife, concealed, in the open position, it would be illegal. Contrary to popular belief, the number of edges a knife has is never mentioned in the CA Penal Code and to my knowledge, no current case law addressed the legality of a double edged knife.