From the NSW legislation... small matters like this are generally consistent across all jurisdictions:
https://www.legislation.nsw.gov.au/#/vi ... part7/div7Division 7 Number-plate lights
86 Number-plate lights(cf ALVSR 2015 r 86; 2007 reg Sch 2 cl 99)
(1) At least 1 number-plate light must be fitted to the rear of a vehicle.
(2)
When on, the number-plate light or lights must illuminate a number-plate on the rear of the vehicle with white light, so the characters on the number-plate can be read at night 20 metres from the rear of the vehicle.
(3) A number-plate light:
(a) may be combined with another light, and
(b) must not project white light to the rear of the vehicle except by reflection, and
(c) must not obscure the characters on the number-plate, and
(d)
must be wired to come on, and stay on, when a parking light, headlight or tail light on the vehicle is on.
(4) Subrules (2) and (3) apply to a number-plate light used to illuminate an auxiliary number-plate issued in respect of a vehicle as if the auxiliary number-plate were a number-plate on the rear of the vehicle.
I might be wrong.
2005 SR Hilux 1KD - SOLD
2009 BMW X5 - destroyed by a hail storm
2012 Range Rover Sport SDV6 - SOLD
2015 Ford Ranger