Concerning the Privy Council declarations of 1960 and 1917, on most occasions when I have inquired or commented on the potential legal restrictions which they may or may not impose on female-line descendants of the Windsor and Mountbatten-Windsor families, members of this forum have answered that the vast majority of UK children are given their father's name and the female Windsors and Mountbatten-Windsors are guaranteed to follow tradition. I am well aware of all of this, and have said as much many times. I simply do not see how it is relevant to the legal questions involving the Privy Council declarations.
However, it is obvious that many do consider it to be relevant, so perhaps there is a point I am overlooking. Could anyone explain how the law, or the interpretation of the law, is affected by the tradition?
Well the tradition of taking the father's surname, especially when the parents are married is likely a large reason why the declarations were worded like that for female line descendants in the first place. And why M-W would only ever have been considered potentially necessary if a baby was born out of wedlock. Because it was taken for granted that
I think it's at least semi relevant because of the above and because it also governs the likelihood of say Bea or Eugenie from wanting to use M-W and potentially challenge the ruling even though they are married. Or Lady Gabriella Kingston for someone non Mountbatten.
If the UK had a tradition of using both parents names or choosing which parents name to use then it might have been written differently in the first place. Especially as particularly in 1917 it would have been assumed that most of the female descendants would be marrying royalty or aristocracy who had their own pedigree/name to pass on like the Earl of Harewood.
I also think tradition is relevant to the discussion because whilst it has nothing to do with what's actually legal or not for Princesses or Lady X Windsor etc the fact that Zara Phillips for example did not use Phillips-Tindall for her children despite being definitely "legally allowed" to potentially shows that the declarations of the privy council are not the only thing stopping us from having Sienna Elizabeth Mountbatten-Windsor-Mapelli-Mozzi.
All in my opinion.