Everybody knows what this means.
Numerous sources sell “tactical knives,” which are designed to look cool, and possibly to be more effective at stabbing people to death.
You can’t use the “military-type” potential of the weapons you sell as their chief selling point and then turn around and say classifying them as “military-grade” is illogical.
The guys arrested were apparently felons and barred from having weapons, which might include knives as well as guns.
Have no clue about how whether such a guy can possess a paring or chef’s knife.
BTW, they’ve had strict “knife control” in UK for a long time.