Kate Middleton's family has had a coat of arms designed, which will feature on the souvenir royal wedding programme.
A coat of arms is a symbol to represent a person or family. The Middleton's design features three acorn sprigs - one each for Kate, her brother and her sister.
Acorns come from oak trees, which are traditional symbols of England. Many grow in west Berkshire where the Middleton family live.
The man in charge of coats of arms, Thomas Woodcock, says Kate was involved in the design and the acorns were her idea.
This is Prince William's coat of arms. Kate will use her one until her wedding day. After that it will be combined with Prince William's.
Here's what the cover of the wedding programme will look like. Prince William's coat of arms will be on the front and Kate's will be on the back. And it looks like it will cost £2!