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,

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. https://en.wikipedia.org/wiki/Pocketknife https://en.wikipedia.org/wiki/Pocketknife Buck also has many knives they specifically call "pocket knife" that have a blade longer than 3 inches: https://www.buckknives.com/collections/pocket-knives/ https://www.buckknives.com/collections/pocket-knives/