I know that when I once registered one of my previous boats the
registration office gave me a document that explained what each letter and number meant. I'm sure the transport department could help you. I notice that in the numbers that you show there is a WA. Maybe that is Western
Australia. Because
registration is a state concern they all insist on having their own way of doing it and like to be different. If you
google WA registration office or what ever they call themselves over there, you may find something. Best of luck with it.