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
Maritime flag head of the ship. These are usually flown while not underway and when the ship is dressed on special occasions. Jacks in the Royal Navy must be run up when the first line is ashore when coming alongside. On 16 January 1899, commissioned ships of the United States Coast and Geodetic Survey were authorized to fly their own flag to distinguish them from ships of the United States Navy, with which they shared a common ensign. Although they continued to fly the same ensign as U.S. Navy ships, ships of the Survey flew the Coast and Geodetic Survey flag as