I'm not attacking you there, just pointing things out. Since grammar is very important when examining law, let's look closely at the semicolon for practice. It is being used in one of two ways. Either it is joining the "slang" and "meaning" parts together like this: "originally burglars' slang for "crowbar;" meaning "policeman's club"" or it is being used as a part of a list as a sort of "greater comma" like this: "Here are three examples of familiar sequences: one, two, and three; a, b, and c; first, second, and third." If it is the second, then it is not related to burglars' slang, and it is readable as: "club, 1848, American English, meaning "policeman's club"". Either way you look at it, it does mean "policeman's club". So to answer your question: yes, I know the difference between a semicolon and a comma, now you do too. Now take a breath and relax. I'm not out to get you. If you have anything to prove your point I would like to see it. I can't really put it any more politely.
Yes, the CA penal code was adopted in 1872, but it was updated in the last 5-10 years. Because it was updated, we can look at the latest revision as applicable "since only the latest version is at all relevant". In the latest version (as I pointed out earlier) we know that the law is very specific in scope because the difference between a sap and a blackjack is not big, but it makes that distinction regardless. It even goes so far as to include both "sandclub" and "sandbag" both of which are obviously quite similar. The sand ones are more similar that "billy" and "collapsible baton", thus one can only infer that they intentionally left out the batons.
Additionally, for it to be banned by the CA penal code, a collapsible baton must be an "instrument or weapon of the kind commonly known as a billy, blackjack, sandbag, sandclub, sap, or slungshot". This means that the club part is not the important part, but the "billy". And as the historical data shows, the law has changed in innumerable ways, but the popular and even the legal definition of "billy" in this context is and has been clearly and strongly defined for centuries. As I said earlier, it is so strongly ingrained into popular knowledge that it is part of halloween costumes even for kids (see earlier img). Ergo, vis a vis, concordantly, quid pro quo, Clarice, the definition does not cover collapsible batons because the law simply does not mention them.
A baseball bat is not a billy, a tire iron is not a billy, a nunchuk is not a billy, a tree branch is not a billy, a chair leg is not a billy. Why, then, do you think that a collapsible baton is? If they meant weapon, then they could just have put "blunt, striking weapon", but they didn't.