Expert System - Australian Flags by McGoo Software

Based on the responses you have made:

The flag is most probably the state flag of Queensland

Conclusion Notes:

The flag of Queensland is a British Blue Ensign defaced with the state badge. The badge depicts a light blue Maltese cross with a St Edwards Crown in the centre of the cross, all on a white disc. The original badge was designed by the then Queensland Colonial Secretary and Treasurer William Hemmant. According to Frank Cayley's book Flag of Stars no one knows why the Maltese cross was chosen. The common assumption that the badge was inspired by Britain's most famous award for bravery, the Victoria Cross, has not survived historical examination. The design of the Royal Crown in the state badge is altered whenever there is a change in the style of crown chosen by the reigning Monarch. The last such change occurred in 1953 after Queen Elizabeth II adopted the St Edwards Crown upon her Coronation in 1952.

Expert System Rule:

IF on the flag the Southern Cross is not visible
AND on the flag there is a Union Jack present
AND the symbol on the fly of the flag looks like a cross
AND the colour of the cross is light blue
THEN the flag is most probably the state flag of Queensland.

Calculated Certainty Factor: 0.71 = most probably