Originally Posted by
lordloocan
The flag illustrated on the login page is known as The King's Colours or Great Union Flag. It 'officially' stopped being used in 1801 with the addition of flag of St.Patrick. However it is still used on non-governmental and civilian buildings and is still seen by many as the flag which represents the King/Queen rather than the UK/GB, though the Royal Standard would be a better choice.
The reason the Welsh dragon does not appear on the Union Flag, often incorrectly called the Union Jack (Only this when flown on a naval vessel) is that the Wales had been annexed by Edward the 1st and was seen as part of the Kingdom of England and so is represented by the flag of England.