This is incorrect. Troops can fly the flag on their own vechicles.
They were told not to raise the American flag IN PLACE OF THE IRAQI FLAG.
I did not make it up and did not dream it - although I don't take everything I read as gospel. It said 'on the vehicles' because we are an army of liberation - not a conqueror (probably not word for word)
I am going to have to start copying these strange things.