Actually, only members of the Royal Family who perform official Royal Duties are mentioned in the Court Circular. Thus, the activities of Prince and Princess Michael of Kent are NOT mentioned in the Court Circular unless the particular activity concerned is one connected with the Sovereign or other other official activities....
As I have recorded elsewhere. the Queen decides who is a member of the Royal Family. This includes both Royals who undertake official Royal Duties [i.e. those who receive Civil List or 'equivalent payments] and also includes Prince and Princess Michael of Kent. The rest of the family, even those who are very closely in the line of succession, are Royal relatives. They are still regarded as very important in some cases - for example, when Peter Philips joins a Sandringham shooting party, he is still addressed very formally as 'Sir' even though he has no royal title.
So far as ex-members of the Royal Family are concerned, it was specifically provided that Diana, Princess of Wales, was still regarded as part of the Royal Family following her divorce and it was also announced that she would still recieve important 'royal' invitations. By contrast, Sarah was NEVER regarded as part of the extended royal family after her divorce. Neither was Lord Snowdon, although he remains on cordial relations with the Royal Family.
I did not say that Prince Michael's day to day engagements are recored in the Court Circular and I understand why. But, when I said that they are mentioned in the CC as members of the Royal Family, along with some other persons we can surely call royal relatives, as you said, I meant such occassions when they attend a larger particular event, when there is a gathering of Royals, such as State banquets, weddings (for example, Prince William's) and Trooping the Colour. The Michael of Kents are also always mentioned when they attend the Queen's garden parties in the season. And when the CC records such event like Prince William's wedding, there is clearly stated that such persons like Peter and Zara Phillips, the St Andrewses, etc., are other "members of the Royal Family". But, of course, it is unqestionable that they are not members of, as I called them, the official Royal Family, but only of the extended Royal Family.
For an another example, I found that:
http://www.royal.gov.uk/pdf/Coats%20of%20arms/ANNEX%20C%20-%20Royal%20Family%20Aug11.pdf In this appendix to the guidelines of use of the Royal coat of arms and names, there are Her Majesty The Queen, His Royal Highness The Duke of Edinburgh, Their Royal Highnesses The Prince of Wales and The Duchess of Cornwall, Their Royal Highnesses The Duke and Duchess of Cambridge, His Royal Highness The Prince Henry of Wales, His Royal Highness The Duke of York, Her Royal Highness Princess Beatrice of York, Her Royal Highness Princess Eugenie of York, Their Royal Highnesses The Earl and Countess of Wessex, Viscount Severn, The Lady Louise Mountbatten-Windsor, Her Royal Highness The Princess Royal and
Vice Admiral Sir Timothy Laurence, Mr. and Mrs. Peter Phillips, Miss Savannah Phillips, Mr. and Mrs. Michael Tindall, The Viscount and Viscountess Linley, The Honourable Charles Armstrong-Jones, The Honourable Margarita Armstrong-Jones. The Lady Sarah Chatto and Mr. Daniel Chatto, Mr. Samuel Chatto, Mr. Arthur Chatto, Their Royal Highnesses The Duke and Duchess of Gloucester, Their Royal Highnesses The Duke and Duchess of Kent, Their Royal Highnesses Prince and Princess Michael of Kent, Her Royal Highness Princess Alexandra, the Honourable Lady Ogilvy,
Sarah, Duchess of York listed as "members of the Royal Family".
Peter and Zara Phillips, as well as the Linleys (and the Lascelleses when they lived), are not only considered as VIPs in some cases, but as grandchildren of a Sovereign, they also enjoy precedence among other members of the Royal Family and before the Clergy, top of the Queen's gov. and peers. For example, until his recent death, the Earl of Harewood was the last person among the Royal Family males in the top of the order of precedence, immediately after Prince Michael.
As I have recorded elsewhere. the Queen decides who is a member of the Royal Family. This includes both Royals who undertake official Royal Duties [i.e. those who receive Civil List or 'equivalent payments] and also includes Prince and Princess Michael of Kent
Are you suggesting that Prince and Princess Michael are considered as full members of the Royal Family because the Queen decided so? I think PM "has it" from his birth as a Prince of Blood and it was never under the Queen's consideration whether he is or not a member of the so-called official Royal Family.
Under the 1917 Letters Patent, James and Louise would automatically be entitled to the rank and style of HRH Prince/Princess of the UK as male-line grandchildren of The Queen. However, when Edward married Sophie the Palace announced their future children would not hold royal rank, instead being styled as the children of an Earl, with the agreement of The Queen.
Technically, a change in the status of future male-line grandchildren of The Sovereign under the 1917 Letters Patent requires new Letters or a Royal Warrant to be issued. Since The Queen has not done so, legally they retain the right to assume royal rank as adults.
More or less, that's exactly what I said, so I don't know why you are quoting a part of my post?
More likely, however, Charles will issue new Letters Patent once he is King downgrading the status of male-line grandchildren to Lord/Lady Windsor, with only the children of the heir to the throne holding royal rank. This is the real reason for the change for Louise and James.
If Charles did so, there would not be enough number of HRHs in the RF to deal with all this charity events and engagements, openings, meetings, balls and concerts, etc., etc.