ACF (Australian Chess Federation) rating is the nationally recognised rating which is used throughout Australia.
Most major (specifically adult) tournaments are ACF rated, meaning that the outcome of a game affects your rating accordingly.
As of the ACF Ratings list for June 2021, my rating makes me the second highest rated junior chess player in the under 18 category and third highest rated junior chess player in the under 20 category in Australia.
https://auschess.org.au/wp-content/uploads/2021/06/topu18.txt
https://auschess.org.au/wp-content/uploads/2021/06/topu20.txt