The words dagger, dirk, and stiletto are commonly used interchangeably to mean more or less the same thing. I think the definitions should be sharpened up a little (excuse the pun) but no one seems interested in doing that. I tried years ago when I was writing for knife and gun magazines, but it didn't catch on. So what point is there in listing all of them? How about poignards? Or machetes? And is a scramasax legal since it wasn't listed? If not, then why list those others?
It looks to me like a typical tool box has at least a few concealed knives in it, in the form of screwdrivers, and in fact screwdrivers are commonly used as weapons (I would classify them as a stiletto since a stiletto traditionally does not necessarily have a cutting edge). By the definition given a carpenter hammer is a knife too. So are we carrying concealed weapons if we have a tool box in our car? I know guys who just throw tools on the floor of their car; are they illegally carrying weapons?
This whole thing is all nonsense. It makes more sense to say that if something capable of inflicting injury is used as a weapon, even in making a threat, it's a weapon. But the law says citizens have a right to have weapons, so unless and until something is used in an illegal manner, it's ok for us to have it.