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 the Northern Territory feature the colour blue). The Southern Cross appears as five white stars on a black panel at the hoist. In the fly of the flag is a stylised Sturt's Desert Rose, the territory's floral emblem since 1961, with seven white petals and a black seven-pointed core. The seven white petals represent the six Australian States and the Northern Territory. Flag of the Northern Territory The current state flag of the Northern Territory was officially adopted by the Northern Territory, Australia, in 1978. The Northern Territory has been in existence since 1911, but did not hoist its first flag until self-government