Our national flag of Stars and Crosses proudly displayed on its 103rd birthday The Australian National Flag should be displayed only in a manner befitting the national emblem. It should always be flown aloft and free and should not be allowed to fall or lie upon the ground.

When hung against a surface whether horizontally or vertically, the top left quarter (Union Jack) should be placed uppermost on the observer's left, as viewed from the front. When suspended vertically in the middle of a street, the top left quarter should face the north in an east-west street, and face east in a north-south street, thus being on the left of the observer facing east or south respectively.

In a line of flags representing a number of sovereign nations, where there are three or more making an odd number of flags, the Australian National Flag should be flown in the centre when only one Australian National Flag is available.

If there is an even number of flags representing a number of sovereign nations, the Australian National Flag should be flown on the left of the observer facing the flags.

In a semi-circle of flags representing a number of sovereign nations, the Australian Flag should be in the centre.

For more check out - Australian Flag Protocols and this protocol document.