Hmm, how is it actually regulated? So, e.g. if I am going to my friends and carrying a bottle of wine altogether with pocket knife bundled with a corkscrew to be sure I will be able to open it, then I am in a grey zone or even illegal?
https://news.ycombinator.com/item?id=15372404
The first man mentioned in that article was convicted and sentenced to 6 years in prison on the sole charge of possession of this knife.
https://www.amazon.com/Sheffield-12113-One-Hand-Opening-Lock...