The rigid class system in Britain clearly defines the invisible barrier that separates royalty from ordinary folks. The Royal Protocol is the standard decorum of the court and strictly imposed in the Kingdom. It refers to the proper flow of the activities of the royals including the discipline, formality and lifestyle. This decorum is the basic guide for commoners how to treat royal family members.
There's also an unwritten rules of "order of precedence" for men and women in the realm that traditionally followed. In the hierarchy of royals and nobles, royals come first with the ruling sovereign as the highest order of human being. The commoners including those royal members should give bows and curtsies when facing the monarch and should move slightly backward when the sovereign is approaching. This royal treatment fascinated the young Elizabeth, when the future Queen was 10 years old, according to the book of Kitty Kelly "The Royals", she slipped from her nanny and paraded back and forth at the palace corridor where the scarlet uniformed guard, clicked his heels, present an arm with his rifle and stood ramrod each time she passed.
The royal engagements should be planned 6 months before the actual date, this is carefully organized by the staff called courtiers, they also determined the kind of speech and audience the royal members should uttered or faced. The audience would not raised questions without the consent of the courtiers. The monarch should be addressed properly with "Your Majesty" and the members with HRH style is "Your Highness". Children of the sovereign would have "The" before their names, example: The Princess Anne or The Prince Charles.
In attending church ceremony, the royal family members occupied seats on the right area of the church and would not be mixed by people without any titles or significant positions in the government. In public sport events, they seated in a specially designated area called the "royal box".
During ancient times until the early 20th century, divorce and homosexuals are not permitted to join the royal circles or be in the presence of the monarch. This prompted one reporter to say "It is possible for a divorce person to enter the Kingdom of God but not in the Palaces of Great Britain". In 1953, Princess Margaret was forced to renounce her relationship to Group Captain Peter Townsend because he was a divorcee. But in the early 1990 all children of the monarch (except for Prince Edward who just married in 1999) ended their marriages in divorce and the sweeping changes in protocol occured.
The order of precedence for men in the UK: The highest being the Duke of Edinburgh because he is the husband of the monarch, followed by his son Prince Charles, the Prince of Wales then Prince William because he is the future king then the Duke of York then the Earl of Wessex. Important note: the order of precedence is different from the line of succession to the British throne.
This is the order of ranking among gentlemen in the realm. HRH with a Prince title should comes first followed by Dukes with HRH status and Earls with HRH style. For women, the Queen is the highest ranking female, followed by the Queen mother( if she's still alive) then the Princess of Wales (if there is). In the case of Camilla Parker Bowles, technically she is the Princess of Wales because she is the wife of Prince Charles, but she choose to be known as Duchess of Cornwall, taken from the secondary title of her husband, Duke of Cornwall.
In the order of precedence in Britain, Duchesses come after the Princesses, so Camilla's ranking is below HRH Princess Alexandra, the Honorable Lady Angus Ogilvy (the Queen's cousin). Presently, the Queen is followed by her daughter HRH the Princess Royal then Princess Alexandra, the Duchess of Cornwall then the Countess of Wessex.