Lincoln. Under definitions 9.36.150
Knife shall mean any dagger, dirk, knife, or stiletto with a blade over three and one-
half inches in length or any other dangerous instrument capable of inflicting cutting, stabbing, or
tearing wounds
Based on this definition, I'd suggest being careful how you carry things like screwdrivers (commonly used as weapons) and Pencils (also used as weapons).
Are there any kind of criteria given anywhere for what constitutes a "dangerous implement?" My opinion is if it's used as a weapon (even if only to make a threat), and has the ability to be used as such, then it's a weapon; otherwise it should not be seen as one by the law, unless it's specifically designed to be a weapon, as in the case of a dagger for example. But otherwise, based on the term "dangerous implement capable of... cutting or... tearing," a judge could order everyone to have their teeth pulled, because they certainly meet the definition, and they're concealed unless we're smiling (and the smile is even better concealment when it comes to knives). I don't expect that to happen of course, but it does illustrate the kind of problem use of poorly-defined terms can cause when laws are written (especially when the laws are illegal in the first place).