Thanks for bringing your direct knowledge to the thread. I don't follow the connection between importation and interstate transport - and you say Customs has no direct role in interceding in interstate transport, if I understand correctly - but I'm more interested in the one-handed lock-back knives. The revocation letters mentioned several times that knives where a flick of the wrist will open and lock the blade, once the blade has been moved out of the closed position a small amount, as via the tab or hole common on many of these knives, are now being called switchblades by Customs. These knives are specifically identified as legal in California - if there is any resistance to opening that must be overcome in moving the blade slightly from its closed position - to distinguish them from illegal gravity/inertia knives. This provides a clear and crucial test for distinguishing legal from illegal knives. I expect that at least some of the opening motion of any lockback knife can be completed by flicking the wrist, once the blade is opened far enough - where that point is varies considerably by model. But those revocation letters appear to open the door for re-defining any lockback knife as a switchblade.