London (CNN)Britain's Duke and Duchess of Sussex are now proud parents to a baby boy. But one mystery still remains: What name will they bestow upon him?
Will it be Arthur or Edward? Anticipation grows over Harry and Meghan's baby name
A giddy Prince Harry spoke to the media shortly after the birth of his son on Monday, telling reporters that the royal couple were "still thinking about names."
"The baby's a little bit overdue so we've had a little bit of time to think about it, that's the next bit," said a delighted Harry during an interview in the royal mews of Windsor Castle.
Like any new parents, Meghan and Harry will undoubtedly have been considering baby names for some time and may have already decided on their favorites.
There aren't any royal rules for choosing names but the British Royal Family likes to honor those who came before them.
Bookmakers have Arthur and Edward, as well as Philip (a nod to Harry's grandfather), among their top choices for a newborn son.
"They will most likely honor the grandparents within the middle names of the child," explains Wendy Bosberry-Scott, spokeswoman for the etiquette experts Debrett's.
"For a boy, the names Arthur, George, Albert, David and Charles are favorites within the senior royals."
We can also count on Baby Sussex being given a fair few names. Queen Elizabeth II bestowed four names on each of her four children. Current heir apparent Prince Charles's full name is in fact Charles Philip Arthur George. Meanwhile new father Prince Harry's full name is Henry Charles Albert David. Harry's brother William, the Duke of Cambridge, has continued the tradition of multiple names with all three of his children.
Baby Sussex will become the seventh in line to throne, but that doesn't automatically make the new addition to the royal family a prince.
Harry's great, great, great grandfather King George V restricted use of the titles Prince and Princess to certain senior members of the Royal Family. However, the Queen could step in to overrule that decree -- as she did with William and Catherine's younger children, Princess Charlotte and Prince Louis.
"If the Queen had not issued a Letters Patent in 2012, Princess Charlotte and Prince Louis would now be styled as the children of a Duke," Bosberry-Scott says. "The 2012 Letters Patent was a reflection of the then-upcoming changes to the Succession to the Crown Act, which in 2013 ended the system of male primogeniture, and meant that Princess Charlotte kept her place in the line of succession when her younger brother was born."
Bosberry-Scott says the baby boy will most likely use his father's second peerage title, Earl of Dumbarton.
Conversely, Harry and Meghan may choose to pass on titles altogether, as Queen Elizabeth's granddaughter Zara Phillips did with her daughters Mia Grace and Lena Elizabeth.
Bosberry-Scott says declining a title is not unheard of. "There have been occasions when a title has been declined, such as when the Honorable Angus Ogilvy -- the younger son of the 12th Earl of Airlie -- married Princess Alexandra in 1963. He was offered an Earldom but declined."
Traditionally, the first to know of a royal birth is the reigning monarch. As well as Queen Elizabeth II, British Prime Minister Theresa May and the Governor General of each Commonwealth nation will be informed, along with the rest of the royals and Meghan's family in the United States.
Ultimately, Bosberry-Scott says the baby's name will be announced "when Buckingham Palace decides to release it."
"Traditionally the official announcement of the birth is placed on an easel just inside the gates of Buckingham Palace, but today social media is also used."
On Monday afternoon, a framed bulletin announcing the birth was placed in the forecourt of the Queen's London residence sans name. And so the wait continues.