As stated above, you have to read your state law and its definitions of the terms. However, if as stated above is true that there is no preemption in your state, like in mine (NY), then you need to look up your city laws, or county laws. You can do this either by contacting a lawyer (and having to pay money), or you could try official channels like calling the police, or local govt (which could take time, and you dont know if who you are asking actually knows the exact laws).
Another problem is that knife terms are in general, very loosely defined. A law may state a "drik" is illegal and yet not clearly define what a dirk is, and it is not the traditional scottish blade. So there is that. It is one of the problems of knife laws in general, they where not wrote by someone who knows knife terminology, but by (usually) idiots.
Usually an "auto" is defined on a state basis by the federal customs definition, which says that it has to have a button in the handle that when you depress, the blade is opened. It has to have a button in the handle, or else it is not an auto, it is an assisted. Thus flippers that are assisted, since you depress an attachment to the blade, not a button in the handle, are assisted, not autos. This technicality is the best aspect of the laws not being wrote by a person who knows knife terminology. As, in my opinion, assisteds would be considered autos if not for that technicality.
Anyway, I ramble. But there you go, the short of it, check your local laws for size restrictions, lock restrictions, and even terms like "threatening shape" which are so loosely defined.
