Royal Standard Flag of the Untied Kingdom
On the Royal Standard, there are four quarterings, two for England (three lions passant), one for Scotland (a lion rampant) and one for Ireland (a harp). Wales is not represented in the Royal Standard, as its special position as a Principality was recognised by the creation of the Prince of Wales long before the incorporation of the quarterings for Scotland and Ireland in the Royal Arms.
The Royal Standard is flown when The Queen is in residence in one of the Royal Palaces, on The Queen's car on official journeys and on aircraft (when on the ground). It may also be flown on any building, official or private (but not ecclesiastical buildings), during a visit by The Queen, if the owner or proprietor so requests.
The Royal Standard is never flown at half mast, as the Sovereign never dies (the new Monarch immediately succeeds his or her predecessor).