Britain

Union Jack
It is often stated that the Union Flag should only be described as the Union Jack when flown in the bows of a warship, but this is a relatively recent idea. From early in its life the Admiralty itself frequently referred to the flag as the Union Jack, whatever its use, and in 1902 an Admiralty Circular announced that Their Lordships had decided that either name could be used officially. Such use was given Parliamentary approval in 1908 when it was stated that "the Union Jack should be regarded as the National flag".

Union Flag
The flying of the Union Flag on public buildings is decided by the Department for Culture, Media and Sport at The Queen's command.

The Union Flag is flown on Government buildings on days marking the birthdays of members of the Royal Family, Commonwealth Day, Coronation Day, The Queen's official birthday, Remembrance Day and on the days of the State Opening and prorogation of Parliament.

It is also flown on St David's Day (Wales), St George's Day (England), St Andrew's Day (Scotland), and St Patrick's Day (Northern Ireland).

it is today flown above Buckingham Palace, Windsor Castle and Sandringham when The Queen is not in residence.

The Royal Arms of Scotland (Lion Rampant) is flown at the Palace of Holyroodhouse and Balmoral when The Queen is not in residence.

On news of a Royal death, the Union Flag (or the Royal Arms of Scotland (Lion Rampant) where appropriate) is flown at half-mast.

Royal Standard
The Royal Standard is never flown at half-mast, as the Sovereign never dies (the new monarch immediately succeeds his or her predecessor).

The Royal Standard is only flown when the Sovereign is present. If the Union Jack is flying above Buckingham Palace instead of the Standard, The Queen is not in residence.

When The Queen goes to Parliament, the Royal Standard flies from Victoria Tower.

Finances of the British Royal Family
From 2013 the Civil list, property services grants-in-aid (upkeep of royal residences), royal travel grants-in-aid, will be replaced by a single Sovereign Grant, which will be 15% of the surplus generated by the Crown estate.

The Crown Estate
"For the year ended 31 March 2011 we returned our best-ever financial performance, recording a net income surplus (profit) of £230.9 million. "

Civil list
The Queen (and only The Queen) receives £7.9m per year.

Sovereign grant bill
Next year this replaces the civil list (and other sources of government funding to The Queen) "The Sovereign Grant Bill introduces a single payment given to the monarch based on 15% of the Crown Estate's revenue from two years previously. … The grant is expected to be £34m in the first year, in line with recent royal spending, our correspondent added."

Principality of Wales
The principality of Wales existed between 1216 and 1542

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 Welsh dragon does not appear on the Union Flag. This is because when the first Union Flag was created in 1606, the Principality of Wales by that time was already united with England and was no longer a separate principality.

Addressing the Queen
You can write to Her Majesty at the following address:

Her Majesty The Queen Buckingham Palace London SW1A 1AA

If you wish to write a formal letter, you can open with 'Madam' and close the letter with the form 'I have the honour to be, Madam, Your Majesty's humble and obedient servant'.

This traditional approach is by no means obligatory. You should feel free to write in whatever style you feel comfortable.