<P> In International maritime signal flags , 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 . </P>
<P> In International maritime signal flags , 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 . </P>
flag flown on a ship to indicate the presence of a disease
flag flown on a ship to indicate the presence of a disease
yellow
yellow