Those posts regarding Austrian aircraft were moved to an own topic here:
http://www.secretprojects.co.uk/forum/index.php/topic,21084.msg207997.html#new,
reasons see below:
At the beginning of the war, the Austrian flag still was used on Austrian aircraft, still then mostly of Austrian
production. With the arrival of more and more German aircraft, generally marked with the "Iron Cross",
that flag was painted on additionally, but later it vanished and oly the cross remained- A reason seemed to
be its bright colours, which made those aircraft easier recognisable. Above all, there was the danger of mis-
identifying them for Italian aircraft.
I think, it was a similar case, as the coours of the RAAF during WW II, which were identical to those of the RAF.
And who would dare to call the CAC Boomerang a British aircraft ? 
