There is a lot of confusion surrounding bladed items be they a pocket knife, saws or axes. Knives especially, the law is quite clear but can be a little vague in places, it is likely that it is to allow a sensible Policeman to use discretion. We have some pretty sensible knife laws in the UK that allow you to use a knife for it’s intended purpose – REMEMBER it is a tool for doing a job. The Criminal Justice Act (1988) says that you may carry a knife with a blade length of 3.0″ or less so long as it is capable of folding – so no fixed blade knives as an “Every Day Carry” EDC. It doesn’t actually state within the Act that it cannot be a locking knife but the sensible thing to do is to stick to a product that is less than 3 inches (75mm) and for it to be non-locking if you wish to carry a pocket knife day to day within the letter of the law. There are exceptions to the EDC laws and you should fully research what they are.
If you wish or need to carry a pocket knife or any bladed item then you really need to have “Reasonable Cause”. Within archery I strongly recommended you consult with your Club and the parent organisation on their rules. Ignorance is not a defense, nor in law and you cannot simply say “I forgot”. Even if you believe yourself to be completely innocent of any crime you should, in all cases, consult a Solicitor.