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
Flag of Northern Ireland to show their support for a United Ireland. After the 1998 Good Friday Agreement, flags continue to be a source of disagreement in Northern Ireland. The Agreement states that: Nationalists pointed to this to argue that the use of the Union Flag for official purposes should be restricted, or that the Irish tricolour should be flown alongside the British flag on government buildings. Sinn Féin ministers in the power-sharing Northern Ireland Executive instructed that the Union Flag was not to fly from buildings operated by their respective departments. This power was removed from ministers by virtue of the Flag Regulations