This Saturday, Meghan Markle will say, “I do” to Prince Harry and become a member of the royal family. But that won’t make her a princess. Due to royal protocol, Markle will have a different title once she marries Prince Harry. And if royal titles baffle you, here’s what you need to know.

According to royal customs, you can only be called a “Princess” if you meet one of two conditions. First, you must either be the daughter of a prince. Or, you have to marry a prince.

You might say, “Wait a minute. Isn’t Markle marrying a prince?” Well, she certainly is, but since Prince Harry is sixth in line to the thrown, Markle will not become a princess.

So, what will she become?

When Prince William married Kate Middleton, the Queen bestowed on him the title, Duke of Cambridge, making Middleton the Duchess of Cambridge. In similar fashion, it is very likely that Prince Harry will be granted royal dukedom after he gets married.

If that’s the case, sources say he could become the Duke of Sussex after marrying Markle, which would make Markle Her Royal Highness the Duchess of Sussex.

There is a chance that Markle could have the royal title of “Princess”, however it would mean going by the name Her Royal Highness the Princess Henry of Wales, referring to her husband.  That’s because only princess born to the title can use their own names.

While this is not unheard of, it seems unlikely that Markle will take this route.