Expert System - Australian Flags by McGoo Software

Based on the responses you have made:

The flag is most probably the state flag of Western Australia

Conclusion Notes:

The flag of Western Australia is a British Blue Ensign defaced with the state badge. The badge depicts the native Black Swan on a yellow disc, with the swan swimming towards the hoist. A variant to this design renders the swan more artistically and includes water ripples. The black swan has long been a symbol of Western Australia. The original colony was in fact called the Swan River Settlement, and in 1870 Governor Weld suggested that the black swan would be the obvious choice of badge for the colony - as it "has been always considered as its special badge, or cognizance."

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 bird
AND the bird is a black swan
THEN the flag is most probably the state flag of Western Australia.

Calculated Certainty Factor: 0.72 = most probably