LONDON (AP) ― If you’re invited to the royal wedding, don’t go buying Kate Middleton an engraved gift ― the poor woman doesn’t know yet what her title’s going to be.

She will be a princess, possibly a duchess, perhaps even a countess. But the exact title is unlikely to be divulged until shortly before April 29, the day she officially joins “the firm” ― as the lordly British royal family is known.

Most women face a straightforward choice when they prepare to walk down the aisle: Take their husband’s name, keep their own, or combine the two with a hyphen. But Middleton’s title, which will dictate what she is called, will be determined by Queen Elizabeth II, not Middleton herself.

Some of the options are not great. Royal experts say it is possible Middleton could end up with the formal name Her Royal Highness Princess William of Wales, a moniker that deflates the aura of the fairytale nuptials. The title makes sense from a traditional point of view ― and that’s important when dealing with the queen and her minions ― but it’s just not very feminine.

“It’s not feasible for her to be known as Princess William of Wales,” said Noel Cox, chief of the legal department at Aberystwyth University in Wales. “It’s not comfortable. I don’t think they’ll do that.”

The rules and precedents that will guide the queen and her inner circle have been in use for centuries ― and some of those conventions are showing their age.

Royal biographer Hugo Vickers said the types of names that have been used in the past ― Princess Michael of Kent is a good example ― do not sound right to contemporary ears.

“Those kind of titles are out of date,” he said. “But theoretically she can’t just be called Princess Catherine, that would imply that she was the daughter of Prince Charles rather than the daughter-in-law.”

He said, however, the queen has the authority to do as she sees fit after consulting her advisers and could make Middleton Princess Catherine despite this technical obstacle.

“They can do what they want,” he said. “I think Princess Catherine has a nice sound. I say why shouldn’t she be Princess Catherine since she’ll become Queen Catherine.”

The dilemma arises in part because of the queen’s extremely long reign. Since she is still in power after nearly six decades, her son, Prince Charles, as heir to the throne, still holds the title of the Prince of Wales.

That means William has not yet become the Prince of Wales ― a title that traditionally goes to the heir to the throne ― and does not hold a formal position, like the Duke of Cambridge, that could be automatically bestowed on Middleton, making her the Duchess of the same place.

If Charles were already king, William ― as heir to the throne ― would almost automatically have been made the Prince of Wales and his new bride would become the Princess of Wales, the title once held by the late Princess Diana.

Since that is not the case, she would technically become “HRH Princess William of Wales” when they marry ― unless the queen first makes William a duke, which would make Middleton a duchess, or makes him an earl, which would make her a countess.

Everyone got that?

There is little doubt that a title like “the Duchess of Cambridge” ― one of the localities that is available ― would be preferable to “Princess William of Wales” for Middleton, so some experts believe the royals will go this route. It also fits in with the tradition of giving a prince a dukedom or an earldom when he takes a bride.

When the queen’s youngest son, Prince Edward, married in 1999, the queen made him the Earl of Wessex on the occasion, and his bride Sophie became the Countess of Wessex.

Others believe William might politely turn down the honor, since he is already well known throughout the world as Prince William, and may harbor plans to eventually streamline and modernize the monarchy by making it less formal.

But royal commentator Dickie Arbiter said it is highly unlikely William would turn down a dukedom.

“It’s a courtesy title that will fall away once William becomes Prince of Wales, and it would be more convenient in terms of Catherine,” he said. “And it would be a helluva story if it became known the queen offered him a dukedom and he turned it down.”

In some circles, the whole question of titles has already been resolved. Regardless of what the queen does, Arbiter said it is likely that Middleton will be known ― at least to Britain’s tabloid newspapers and their millions of readers ― as Princess Kate.