The Queen will keep the baptism certificate for her latest great grandchild a secret as part of Harry and Meghan's efforts to keep Archie's godparents private.
The Duke and Duchess of Sussex had already refused public access to today’s ceremony and banned television cameras from filming guests arriving.
The christening is set to be a private affair and the Queen, Archie's great grandmother, will help by keeping the baptism certificate private.
And the couple's choice of venue, the Queen’s Private Chapel at Windsor Castle, helps their quest for privacy.
Normally the godparents’ names would be among the christening details recorded in a parish church register that anyone could look at on request.
But the tiny venue for Archie's ceremony, which is separate from St George’s Chapel where the Duke and Duchess married, is a ‘Royal Peculiar’.
Under archaic rules this means godparents will remain anonymous.
In the past the Queen has kept baptism certificates for other royals secret, it is understood.
However this was never raised as an issue because previously the godparents names were released publically.
A Church of England spokesman confirmed the royals did not adhere to the normal requirements, saying said: “Under the Parochial Registers and Records Measure 1978 all baptisms must be registered and the record made is normally publicly available for searches and for the making of certified copies of entries.
“However the register to be used in this case is held privately by the Royal Household on behalf of the Crown and we understand that it has never complied with the usual requirement.”
Among the guests today will be the Prince of Wales, Duchess of Cornwall and Duke and Duchess of Cambridge.
It is understood the Queen will not be attending, due to a prior engagement.
Instead of having press photographers, fashion photographer Chris Allerton, who took their wedding photos, will capture the special moments.
The first pictures are expected later this afternoon.
