If it is set by default in the system it is still a unique one in the YMMM / YBBB Airspace. Even the Japanese changed it a while back that you have to send the position on each reporting point. They are now satiesfied with the ADS in automatic mode. Maybe Aussie technology is not that advanced???
Captain Dartīs opinion about the downunder system still stands.
Fly safe and land happy
NG