St John Ambulance Australia employs the use of ranks, as an organisation with its roots in the military. Its rank structure is based upon that of St John Ambulance in the United Kingdom, while also taking inspiration from the Australian Army.
Recent changes
In the mid-2000s, the rank of Sergeant-Major was abolished from the State/Territory level, having already been abolished at a divisional level earlier.
References
St John Ambulance Australia ranks and insignia Wikipedia(Text) CC BY-SA