Quarantine "yellow jack" but this was also a name for yellow fever, which probably derives its common name from the flag, not the color of the victims (cholera ships also used a yellow flag). The plain yellow flag ("Quebec" or Q in international maritime signal flags) probably derives its letter symbol for its initial use in "quarantine", but this flag in modern times indicates the opposite—a ship that declares itself free of quarantinable disease, and requests boarding and routine port inspection. Australia has perhaps the world's strictest quarantine standards. Quarantine in northern Australia is important because of its proximity to South-east
Flag of New South Wales 1865 in which all colonial vessels should "wear the Blue/Red Ensign with the seal or badge of the colony in the fly thereof". New South Wales then adopted a second flag in 1870 and it was almost identical to that of Victoria (with gold stars; 5, 6, 7, 8, 9 points). This flag was also a defaced British Blue Ensign with the "Governor's Badge" located in the fly. The badge was the Southern Cross and an imperial crown situated above the Southern Cross. The difference between this flag and that of the Victorian flag was that the stars were gold