ROYAL NAVY FLAGS
Above- The Union Flag. This is commonly, but mistakenly called the "Union Jack". The only time it is referred to as such is when a Royal Navy ship is in port and is flying this flag on her bows.
Above- A Rear-Admiral's flag. This denotes the command of a Rear-Admiral.
Above- The White Ensign. This flag is flown from all Royal Navy warships. In times of battle, warships would often fly one or more larger versions of this flag known as "battle ensigns".
Above- A Vice-Admiral's flag. This denotes the command of a Vice-Admiral.
Above- An Admiral's flag. This denotes the command of a full Admiral.