Do you have a citation for that? Most people would not consider a 3+ inch blade a pocket knife and even then it’s not illegal if you have a good reason:
That’s a hunting knife with a belt holster. It might be popular but usually “pocket knife” means something like a Swiss Army knife which comfortably fits in a normal sized pocket.
(Nothing against Buck Knives, by the way - I have one of the first ones made in the custom knife shop 25 years ago when I developed the web UI for them. It’s just not a daily carry kind of size for most of us.)
I don't think that's true. Where I grew up everyone carried a knife like this and called it a "pocket knife", and the description on wikipedia, various stores, blogs, manufacturers, etc all use the term to refer to this sort of knife.
Good point, although I notice that they seem to top out that category at 3¾ inches so maybe part of what we’re seeing is that standards have been evolving over time to shorten the blades.
Oh, I’m very aware of that. I was just looking for examples of someone in the UK actually going to jail for carrying a normal pocket knife where they weren’t threatening people or trying to enter some kind of restricted space.
https://www.gov.uk/buying-carrying-knives