Sunfish, I hadn't heard of that, but it would explain why recently in Victoria (as a P plater) I was 'waved past' by an RBT late at night when usually the police are very interested in P platers.
Yup, I was made aware of this through "semi official sources". If you are a "cleanskin" or the car you are driving is registered to a "cleanskin" and the cops are reasonably busy, you can expect to be waved through. It's happened to a few perplexed friends as well.
Please note that not all RBT operations use this technology. You will also see strategically placed unmarked cars on major highways and arterial roads from time to time - they are looking for unregistered vehicles or vehicles registered to drivers who have lost their licence, or don't even have one.
The use of this technology, if its coupled with train bus and aircraft ID requirements, gives a government complete control of individual movement. The Soviet Union had internal passports for this purpose.