Officially, the current Australian flag is the blue ensign which was adopted with the Flags act 1953 and is representative of maritime/ corporate law. This followed the 1948 Citizenship Act. An ensign is the national flag flown on a vessel to indicate nationality . There are three ensign flags, red (civilian ships), light blue (Royal Australian Air Force) and white (the Royal Australian Navy) all represent maritime/ corporate law.

The flag that represents the Commonwealth of Australia Common Law is the 1901 flag. This is distinct from the red ensign flag.

The original Australian flag following federation
The original common law land flag is in the ratio 3:2.

The white flag, may also have value, as it implies that you are a non-combatant, and so protected by the Geneva convention.