O dear Creamy, like some others here you seem to have you own idea on this matter. Suggest you check AIP for the relevant definitions. The refs are GEN 22-17 & 22-24. Oz runways does not permit cut & paste, so follows from another source.
Common traffic advisory frequency (CTAF), is the name given to the VHF radio frequency used for air-to-air communication at US, Canadian and Australian non-towered airports.
In Australia, there are many landing strips in remote locations that have CTAF operations 24 hours a day, seven days a week. There are also CTAF(R) landing strips which require the aircraft intending to enter the area of operation to be fitted with a radio. The most common CTAF frequency is 126.7 MHz at non towered aerodromes except for when two CTAF airports are near each other. Aerodromes using CTAF outside tower hours typically nominate a frequency that is used during tower hours.
A UNICOM (Universal Communications) station is an air-ground communication facility operated by a non-air traffic control private agency to provide advisory service at uncontrolled aerodromes and airports and to provide various non-flight services, such as requesting a taxi, even at towered airports.(on another frequency)
A bit like FS if you are that old!
The MULTICOM is not the G frequency, never has been. All references to the MULTICOM in Oz are to 126.7 only. What we have now, like it or not is that the G frequency is by default the area frequency on which various ATS is provided including ATC.
A Unicom on the other hand is a service usually provided on the CTAF, be it the MULTICOM or the promulgated CTAF frequency.
Re your second last para... The controversy as you say it, only came to light because someone in CASA, like you did not understand what was in place already and thought it should be changed, and had the power to do it, not really understanding that it was a change and therefore not conducting a risk analysis.
All this because they did not bother to ask!!
