[AndrewOMartin]

You can carry a knife with a blade up to 3" as long as it's non-locking (i.e. flips open and closed like a Swiss army knife and you don't need to hold a button to close it). You can also carry much more dangerous stuff like a scythe but you need to prove you've got a good reason (like it's your trade) and I think it needs to be wrapped or covered somehow to stop some scallywag grabbing it.

Unless I'm wrong, which I likely am.