Quarantine with a disinfecting stove, have a right to navigate the Canal, in quarantine, subject only to the landing of those who were suffering from plague. Plain yellow, green, and even black flags have been used to symbolize disease in both ships and ports, with the color yellow having a longer historical precedent, as a color of marking for houses of infection, previous to its use as a maritime marking color for disease. The present flag used for the purpose is the "Lima" (L) flag, which is a mixture of yellow and black flags previously used. It is sometimes called the
Flag of Australia treated with respect and dignity it deserves as the nation's most important national symbol". The National Flag must always be flown in a position superior to that of any other flag or ensign when flown in Australia or on Australian territory, and it should always be flown aloft and free. The flag must be flown in all government buildings and displayed in polling stations when there is a national election or referendum. Private pleasure craft can fly either the Red Ensign or the Australian National Flag. The British Blue Ensign can be flown on an Australian owned ship instead of