Ascot is one of the sporting and social events of the year
Royal Ascot begins on Tuesday and as well as top-class racing there will be plenty of interest in the fashion on show over the five-day meeting.
There are certain rules that have to be followed in the Royal Enclosure - women have to wear formal day dress, with a hat or fascinator, while off-the-shoulder, halter necks, spaghetti straps and mini skirts are all forbidden.
Men have to wear black or grey morning suits, including a waistcoat, along with a top hat.
It sounds simple to follow but every year there are those who try to bend the rules and end up creating a stir.
Fashion critic James Sherwood, who will be part of the BBC's team at Royal Ascot for his fifth year, gives some tips on what to expect at the meeting and how to avoid those fashion faux pas.
WHY IS ROYAL ASCOT AN UNIQUE EVENT ON THE FASHION CALENDAR?
Ascot is one of the last great social occasions anywhere in the world where formal day dress is worn. You rarely see morning dress worn anywhere else except at the grander English weddings, Trooping the Colour and investitures at Buckingham Palace.
It is a snapshot of a dress code that does not exist outside Royal Ascot week.
There is nothing better than when you are in the Royal Enclosure track side and see the charming colour spectrum when all the ladies come out to watch the race. It is like a field of flowers and is a truly fabulous sight.
I always look forward to Royal Ascot. There is something 'other-worldly' about being in the Royal Enclosure with everyone dressed in their finery and - one hopes - on their best behaviour as a guest of the Queen.
HOW DO YOU NEGOTIATE THE DRESS CODE?
You should never try to set your own trends at Royal Ascot. It is not the place for fashion experimentation or veering too far from the dress code.
Trying to be too adventurous or aiming to stand out for the cameras, people tend to make an exhibition of themselves and attract attention for the wrong reasons.
Bare feet are a fashion no-no at Royal Ascot, whatever the weather
Dressing in an ultra-conservative, formal fashion in the 21st century you inevitably stand out anyway against all the dross and dressing down. There is no such thing as trying too hard or being too groomed for Royal Ascot.
You should never wear new shoes for the first time at Royal Ascot either but that is just common sense. Even if your feet do hurt in heels all day, it is a cardinal sin at Royal Ascot to take one's shoes off. No-one would have dreamed of doing such a thing one generation ago.
The people that I pick to comment on live at Royal Ascot are not the ones who have gone for a lovely day at the races and put on their Sunday best. They may not be wearing new season couture but they have made the effort.
It is the people who try to dress outrageously to get on the telly who I usually have the sternest words for. This is not How To Look Good Naked.
HOW IMPORTANT ARE ACCESSORIES?
The accessories for Ascot are the key to a successful outfit.
It pleases me to see a simple understated dress accessorised with good family pearls, gloves, handbag, pashmina and umbrella.
The Queen is always immaculately dressed at Royal Ascot
I do not include the hat as an accessory. It is the star of a Royal Ascot ensemble.
As I said, shoes can cause ghastly problems on the turf and there are no hard and fast rules but wearing seven-inch heels clearly is not going to work. Court shoes as worn by Her Majesty are an obvious choice.
The hat is the showpiece and it should be because that is the one thing one rarely wears during the rest of the year, unless you are the Queen.
Matching every element of your outfit can look rather contrived and 1980s unless you are the Queen who, one has to admit, is above fashion. It is wise to have an element of co-ordination but is chic to balance a bright dress with monotone accessories or vice versa.
If you have something vibrantly coloured or extravagantly trimmed on your head, it is rash to wear an equally loud dress or suit.
Fuss only makes an impact when it is contained. The most dramatic, bright hat with a broad picture brim looks stunning when teamed with a plain navy dress.
There is an unspoken rule at Royal Ascot to avoid head-to-toe black unless one is in mourning.
HOW CAN YOU DRESS ON A BUDGET?
The High Street is awash with good, cheap fashion at the moment, which is fine for younger women but it is harder to carry off budget fashion as one gets older.
I would like to think that most women have a pretty good collection of shoes and handbags in their wardrobes that can lift a cheap and cheerful high street dress to Ascot standards.
It is quite chic to go to Ascot in an older dress - maybe something that is a couple of seasons old or a piece you could borrow from granny's attic or smart girlfriends.
If one is vaguely creative, there is nothing wrong with buying a simple high street hat and trimming it yourself.
If millinery is not your forte, find the largest straw saucer of a hat with a picture brim that is both simple and dramatic. There is nothing worse than a loud, cheap overdressed one that makes you look like a Tiller Girl at the Folies Bergere.
A fascinator - a little tuft of feather, tulle or ribbon - can look disarmingly sweet but it has to cover the crown of the head if you have Royal Enclosure badges.
HOW CAN A MAN CARRY OFF TRADITIONAL MORNING DRESS?
Prince Charles follows the rules in his morning suit
Surprisingly, there are more details for men to consider than women: the choice of top hat, the tie knot, the cufflinks, the waistcoat or the handkerchief.
One decision that you can take without anxiety is whether to order a black or grey morning coat. Both are equally appropriate.
Cravats really stand out as the wrong choice at Royal Ascot. Wear a tightly knotted tie.
Shirts should be pale but never white, with corresponding white collar and cuffs. One can play with colours but do not match your tie with your waistcoat and your handkerchief. It looks too much like wedding attire.
Although the tradition for waistcoats is for buff or grey, I will be wearing a blue and a French lavender one and BBC presenter Willie Carson is wearing a buttermilk colour. Colour is much more acceptable than pattern.
Socks should be grey or black. Coloured socks are no longer considered eccentric: they just tend to look second rate.
HOW INFLUENTIAL ARE ROYAL FASHIONS AT ASCOT?
I do not think the Queen or any member of the Royal Family particularly lead fashion trends any more except for Royal Ascot Week - when they set the tone for how people dress and how they behave.
The 1970s were probably the most difficult decade for Her Majesty in fashion. She was most comfortable in the 1950s because the New Look suited her whereas the 70s were far from her comfort zone.
However, in the last 10 years the Queen has blossomed and looks both happy and glorious.
This is thanks largely to her dresser Angela Kelly and younger designers such as Stewart Parvin.
As Miuccia Prada recently said, the Queen is simply the most elegant woman on the planet.
James Sherwood was speaking to Elizabeth Hudson