a yellow flag hoisted by all ships on entering a harbor, to show that it has contagious or infectious disease aboard, or by a ship that has been quarantined
{i} yellow flag flown by itself by a ship requesting pratique on entering a harbor to indicate that the ship has no disease on board; flag flown by a ship with another flag to indicate that it has contagious or infectious disease aboard; yellow flag raised by a ship that has been quarantined