It's something I've extensively researched. I'm 100% sure the regulated definition I've provided is completely accurate. Back in the day they didn't want an idiot to try to operate a cannon or mortar without knowing what was going on. On top of that, incorrectly loaded weapons were also an issue. People don't even think of such things today. Back then you usually brought your own arm. On top of that, militia are expected to fight against or along side a standing army. They didn't want unqualified people doing that. In short, regulated means you are capable of safely operating and maintaining your arm.