The official royal wedding invitations have been sent to almost 2,000 guests to witness as Prince William and Kate Middleton exchange vows at Westminster Abbey on April 29. The gold embossed wedding invitations were sent to members of the royal family, close friends and dignitaries from around the world. The men’s dress code specifies they dress in uniform, morning coat or lounge coat, while reports note that women guests are to wear a hat during the royal wedding ceremony.

Speaking of bridal hats, renowned milliner Philip Treacy of London is rumored to be making a bridal hat for Kate Middleton to wear following the wedding ceremony. Philip Treacy confirmed to several media outlets that he is designing hats for “some members of the royal family and attendees.” Kate Middleton has been seen at high-profile events wearing designer hats by Treacy.