4. Every royal wedding party must include a crop of children.

Because it’s a custom from Britain.
Exception: A best man or maid of honor may be present.
As you may have noticed, photos taken at royal wedding celebrations typically feature a significant number of children. Some American brides and grooms ask that their spouses not bring children to their wedding, but that would be a big no-no in the Royal Family.

Every royal wedding reception requires a large number of children. ©Dave Cannon/Getty Images/GP
According to Elle, it’s customary in Britain for children to serve as pageboys and bridesmaids. Even if royal marriages have maids of honor, they lack the customary bridesmaid/groomsmen arrangements that most other weddings have.