If the linked news report of June 12, 2005 is behind the popular claim that the placement of (some?) blood princesses above married-in princesses whose husbands are absent is only for "private" occasions, then I am not sure the claim is fully made out when one examines the article more closely.
https://www.dailymail.co.uk/news/article-351948/Camilla-Britains-Fourth-Lady-.html
[...]
As the Duchess, looking happy and radiant in an ivory suit and hat, took her place on the Buckingham Palace balcony for the first time, a confidential Buckingham Palace document revealed that she is ranked below Princess Anne and Princess Alexandra in the official list approved by the Queen.
The document, obtained by The Mail on Sunday, is the first to include Camilla since she married Prince Charles - and last night led to speculation of a Royal snub.
Her new position is below that held by Princess Diana when she was married to the Prince of Wales. Then Diana was ranked above all women in the Royal Family apart from the Queen and Queen Mother.
And the Duchess of York, who had a similar title to Camilla, was listed third in the order of precedence when she was married to Prince Andrew.
[...]
But this potential embarrassment is avoided in the new list, marked 'Private' and entitled 'Precedence of the Royal Family to be observed at Court', which in practical terms determines the seating arrangements for State occasions.
In my judgment, the confidential list was marked "Private" to convey that it was a confidential,
private document, not to be disseminated outside the palace. "To be observed at Court" does not necessarily suggest that the list is only applicable to private events.
Continuing with the article:
[...]
But last night Buckingham Palace insisted Camilla had not been demoted by the Queen. A spokesman said: "To reflect the Duchess's wish to be called Duchess of Cornwall rather than the Princess of Wales, the Queen took the opportunity to clarify the private administrative Precedence for the Palace. This is not a downgrading of the Duchess but merely reflects that the Duchess is a Duchess, not a Princess."
[...]
The Palace spokesman's reference to "the private administrative Precedence for the Palace"
may connote "private precedence for administrative purposes". But alternatively, the spokesman's statement could connote "[public or private] precedence, to be privately administered", couldn't it?
That's seems to be a generalization. Only Anne and Alexandra were 'promoted' for private occasions. Royal-born princesses Beatrice and Eugenie are apparently still behind their aunts - unless the queen at a later point included them as well.
May I ask where you know that from? The 2005 report is ambiguous: "below Princess Anne and Princess Alexandra" could reflect a placement directly below them or at some further point below them.
Moreover, in 2005, Princesses Beatrice and Eugenie were both minors and thus may not have been included in the palace's precedence list at all.
Can anyone cite an example where the Princess Royal and the Duchess of Cornwall were present at an event without the Prince of Wales?
According to this column, the Duchess of Cornwall gave way to the Princess Royal at a joint engagement in 2006.
https://www.telegraph.co.uk/news/uk...bridge-to-curtsy-to-the-blood-princesses.html
The Order of Precedence affects other aspects of royal protocol, such as who arrives first at an event. For example, Camilla was forced to wait in the drizzle outside the Guards Chapel, Windsor, for the arrival of Princess Anne at a memorial service in 2006, because Charles had not accompanied her. A Buckingham Palace spokesman declines to comment.