So HJ was just a Holden Commercial?

These modern mid '70's cars are not my specialty. I seem to remember the tailgates got a HOLDEN badge in the centre.

My wifes VE Sportwagon has a Belmont badge on it! It is a Commodore but nowhere can you find a Sportswagon badge even though Holden called them that.
Just when was it Holden stated calling Wagons "Station Wagons" and why?