"I would have no idea what to do," tourist Tracy Tabachow said if she had to attend the reception.
Buckingham Palace and Westminster Abbey, where the wedding will take place, reflect years of tradition and grace.
"For ladies that would mean a nice dress not a cocktail dress, not a long dress, tea length is probably okay," says royal expert Gwynne Gorr. "Gentle accessories, not things that are going to recreate the fashion world with what you've worn."
The guide includes the correct way to use silverware and how to hold a champagne glass.
There is even a very specific way that attendees must greet the Queen.
"Well, you don't shake, you bow. You've gotta bow," says tourist Louise Sudul.
The hundreds of guests may have a long list of tips to remember but they will be able to participate in the event of a lifetime.
"We haven't had a wedding like this of this magnitude on planet earth in over 30 years," says Gwynne.
Liz Cho and Kemberly Richardson report from London all week on Eyewitness News!