Not really a secret trial either Dick.
Like CA/GRS, UNICOM (where provided) is intended only to be a tool to help enhance pilots’ situational awareness, and is not a traffic separation service. Unlike CA/GRS, UNICOMs are not designed to provide any traffic information (Airservices Australia, 2007). From December 2007 to March 2009, UNICOM services were trialled by Airservices Australia at a number of non-towered regional aerodromes where CTAF(R) was used (Dubbo, Hervey Bay, Port Macquarie, Wagga Wagga, Olympic Dam). During this trial, a special dispensation under CASR 139 also allowed these UNICOM services to provide basic traffic information to pilots.
From appendix C to this:
Safety in the vicinity of non-towered aerodromes