Peter Phillips' royal wedding can ignore several rules thanks to the reigning monarch, King Charles III.
When Peter Phillips marries NHS nurse Harriet Sperling this Saturday (6 June), the couple are expected to enjoy far more freedom than most royal brides and grooms.
As the son of Princess Anne and grandson of Queen Elizabeth II, Peter is not a working royal, meaning many traditional expectations simply do not apply.
The relaxed approach taken by King Charles and Queen Camilla during their 2005 wedding also helped pave the way for less formal second royal marriages.
From skipping tiaras to avoiding a televised spectacle, here are seven royal wedding traditions Peter and Harriet can choose to leave behind.
(Max Mumby/Indigo / Contributor / Getty Images) No carriage procession
One of the most recognisable royal wedding traditions is the horse-drawn carriage ride through cheering crowds.
Prince William and Kate Middleton, along with Prince Harry and Meghan Markle, both took part in grand processions after their ceremonies.
However, Charles and Camilla opted for a much more understated celebration in 2005, with no elaborate carriage parade or Buckingham Palace balcony appearance.
Peter and Harriet are expected to follow a similarly private route.
Harriet may skip a tiara
Royal brides often wear historic family tiaras on their wedding day, but second royal weddings have tended to break with tradition.
Both Queen Camilla and Princess Anne chose alternative headwear rather than tiaras for their second marriages.
While Harriet could be offered a family tiara, there is no expectation that she must wear one.
King Charles III and Queen Consort Camilla got married in 2005 (Pool/Tim Graham Picture Library / Contributor / Getty Images) No requirement for Welsh gold wedding bands
For more than a century, royal wedding rings have traditionally been made from Welsh gold from the Clogau St David's mine.
The custom has been followed by generations of royal brides, including Queen Elizabeth II, Princess Anne and Kate Middleton.
Peter has already shown he's happy to do things differently. When he married Autumn Phillips in 2008, he wore a platinum wedding band rather than following royal convention.
A personalised bouquet could replace tradition
Most royal bridal bouquets include a sprig of myrtle, a tradition dating back to Queen Victoria.
The flower is said to symbolise love and a happy marriage, and Queen Camilla included it in her bouquet when she married Charles.
However, second royal weddings often take a more personal approach.
Princess Anne chose a simple bouquet featuring heather for her marriage to Sir Timothy Laurence, setting a precedent Harriet could follow.
Prince William and Kate Middleton tied the knot in 2011 (Chris Jackson / Staff / Getty Images) Less scrutiny over the wedding dress
Royal wedding dresses often attract huge attention and are typically seen as an opportunity to showcase British designers.
Senior royal brides are also thought to discuss their wedding attire with the monarch before the big day.
While King Charles may still get an early look at Harriet's dress, the smaller and more private nature of the wedding means there is likely to be far less pressure than that faced by Kate Middleton or Meghan Markle.
A much smaller guest list
Big royal weddings often attract world leaders, foreign royals, celebrities and politicians.
Prince William and Kate Middleton's 2011 wedding welcomed around 2,000 guests, including David and Victoria Beckham as well as Sir Elton John.
Peter and Harriet are expected to keep things far more intimate.
Charles and Camilla's civil wedding ceremony was attended by just 28 guests, proving a smaller celebration can still carry royal significance.
Prince Harry and Meghan Markle married in 2018 (JANE BARLOW / Contributor / Getty Images) No live TV audience
Modern royal weddings are often watched by millions around the world.
Peter's wedding, however, is not expected to be televised, just as his 2008 wedding to Autumn Phillips remained a private family occasion.
Before her engagement to Peter, Harriet was married to fitness instructor Antonio St John Sperling, with whom she shares a teenage daughter named Georgina.
Peter, meanwhile, shares two daughters, Savannah and Isla Elizabeth, from his previous marriage to Autumn.