Significance of Union Jack British Flag

Union Jack British Flag carries the crosses of St. Andrew, St. Patrick, and St. George. This signifies their respective countries Scotland, Ireland, and England. A red cross on a white field represents England; a white diagonal cross on a blue background represents Scotland while a red diagonal cross on a white field represents Ireland. 

Normally the broader white band is on the upper side while the narrower white band diagonal is at the lower end of the flagpole. You can fly the Union Jack British Flag on government buildings on specific days like:

• Commonwealth Day, which is the second Monday in March
• Birthday of Earl of Wessex, Prince Edward, on 10 March
• Coronation Day on 2 June
• Queen's Birthday on 21 April
• Queen's Official Birthday in June, as date varies each year
• Anniversary of Queen's Accession on 6 February
• St George's Day on 23 April
• Birthday of the Duke of Edinburgh on 10 June
• Birthday of the Duke of York on 19 February
• Birthday of the Royal Princess, Princess Anne, on 15 August
• Birthday of the Prince of Wales on 14 November
• Birthday of The Duchess of Cornwall on 17 July
• Remembrance Sunday in November, as date varies each year
• Queen's Wedding Day on 20 November
• 9 May as it is Europe Day
• St George's Day on 23 April at England only
• St David's Day on 1 March at Wales only
• St Andrew's Day on 30 November at Scotland only  

Ensigns

Union Jack British Flag appears as an ensign on sea vessels and aircraft of the United Kingdom and its overseas territories.

Use and Origin of Unionjack

There are various ongoing debates over the usage of the term Unionjack Flag. Some assert that the term should only refer to the national flag. Some others opine that the term is correct if you flow the national flag as a jack. A jack is a small flag flown at the bow of a ship.

The term Unionjack Flag has been prevalent since 1700s, although there is no clear indication of its origins. Jack could have come from James VI, King of Scots inheriting the English crown. It could be the Latin for ‘James’. 

The Royal Navy was all-powerful at that time. Hence, all ships did use the Jack Staff, which is a flagpole at the bow of a ship. Such regular and rampant usage could be the cause behind use of Unionjack Flag.

Although this term has been in use since the reign of Queen Anne (1702-14), there is no concrete information to ascertain or establish its origin. Some also attribute it is origin to the jackets of Scottish and English soldiers. The jack-ets of these soldiers could have been the cause for inclusion of the name in the Flag.

Present-Day Use

Unionjack Flag originated as a Royal Flag. Nevertheless, many organizations and people fly the flag at various locations. It is also in use as an emblem. Sometimes it also comes as a depiction on some objects. BBC website prefers using the term in the lowercase as union jack due to the extensive confusions and controversies.

The Royal Army does not have any flag of its own. Therefore, Unionjack Flag also serves as the flag of the Army. Previously army men carried it to battles with the regimental colors of the Army. The last time was however in 1881.