OK, here is another way we sort of offend ones new to the sport. Acronyms. I mean it's fine if there is a secret decoder ring or a list somewhere they can use to figure out what someone is saying.
Go over to TFL's FAQ page. Scroll down to and click on 'CLOTFLA' (AKA: Camonical List of TFL Acronyms) under the title Web Acronyms/ Firearms Terms.
You will find a lot of help with acronyms there.