The strict dress code for each of the Royal Ascot's four enclosures

The Royal Ascot is back, with the famous horse racing event taking place between Tuesday and Saturday. Held at the Ascot Racecourse in Berkshire, UK, the five-day event brings together many of the top horses of Ireland and the UK, to compete across 28 races, for a total prize fund of more than Dh38.6million. This year, the event is back to full capacity, with one of the most anticipated fashion events — Ladies Day — happening on Thursday. It's where women turn out in the biggest, most extravagant hats imaginable. To view the race, spectator spaces are divided into four enclosures, each with its own dress code. To help race goers navigate them, Ascot now has its own website and style guide that lists the do's and don't of what to wear, highlighting the importance of getting it right. Scroll through the gallery above to see Royal Ascot looks through the years. Arriving in the wrong outfit will not run the risk of being barred from an enclosure that you have spent a lot to get into, but could have you being asked to leave the event completely. Here, we break it down by area. There are four enclosures, of which only three are open to the public, as the Royal Enclosure is reserved for members and their guests. As the grandest of the four enclosures, there is little surprise it has the strictest rules for what visitors can and cannot wear. Ladies must wear formal daywear to access the Royal Enclosure, which can be a dress or top and skirt, but must fall to below the knee, or longer. Best practice is also to cover the shoulders and upper arms — however, a strappy top or dress is permissible if the straps are wider than 2.5 centimetres. Strapless, spaghetti, halterneck, off-the-shoulder or Bardot necklines are not acceptable. Straps or sleeves must not be sheer or see-through, however, lace is permitted. While trouser suits are welcome, the trousers must be full length, and both elements of matching material and colour. As an alternative, jumpsuits are acceptable, but like hemlines, must fall below the knee. Shorts or anything that expose the midriff are an absolute no-no. Women are required to wear a hat at all times at Ascot, and within the Royal Enclosure, this can also mean a headpiece but only if the solid base has a diameter greater than 10cm. A fascinator is not allowed. Men are expected to dress up too, and a black, grey or navy morning dress, complete with a waistcoat, is required for this area. Men must wear a tie — not a cravat or bow tie — and only wear black shoes with socks. Top hats are also required, but unlike for women, men are permitted to remove headwear if at a restaurant, in a private box, at a private club or at the terrace, balcony or garden. They are not permitted to customise top hats with ribbons, bands or badges, and must not wear a novelty waistcoat. Discreet patterns and anything of a "patriotic" nature is allowed as long as the colours are subdued. So if you have been yearning to wear that Union Jack waistcoat that has been stashed for years, you are in luck, as long as it is not too bright. In every enclosure, those wearing national dress or in military service dress are welcome. As this is still formal, guests are reminded to dress accordingly, however, it is a little more relaxed than the Royal Enclosure. For women, this means the head must still be covered at all times, but now a hat, a headpiece and a fascinator are all deemed fitting. Like the Royal Enclosure, women's outfits must not be strapless, off the shoulder, Bardot or one-shouldered, but a backless dress is acceptable, as long as it is not strapless or any other of the above restrictions. Trousers suits and jumpsuits are both fine but have to follow the same guidelines as the Royal Enclosure, and culottes are also admissible, but only if they fall below the knee. Shorts still are not, regardless of length. Men are required to wear a full-length suit in matching pattern and colour, with a collared shirt and tie. Again, bow ties and cravats are not permitted, and while shoes no longer have to be black, they should adhere to dark colours. Socks also need to be worn and must cover the ankle. Jeans, trainers or chino trousers are off limits. While the written dress code remains the same as for the first two enclosures, in reality, is it far more laid-back. Women must still wear a hat, but this can be extended to a styled turban, a halo of feathers or a fascinator. Separates are now a safe option, but keep things complementary, such as a patterned pink blouse over a plain pink skirt to retain a "polished" air. As this enclosure is on grass, the venue suggests wearing block heels or wedges instead of stilettos to avoid sinking into the mud, and to keep hat sizes small, preferably a fascinator as not to block the view. Men, meanwhile, must wear full-length trousers and a jacket, although these do not have to match, and as before, must wear a collared shirt and a tie. Ties can be colourful, but again, discreet patterning/decoration is encouraged. This has the most relaxed code of all, with suggestions to wear "smart attire" topped with a hat or fascinator. For women, this can mean printed silk pyjamas with a fascinator, or a tea dress with low heels, and a feathered Alice band. Men can also relax, and while encouraged to wear a jacket, collared shirt and full-length trousers, these do not have to match, so enjoy artfully mixing check trousers with a blazer, as long as it comes with a tie.

The strict dress code for each of the Royal Ascot's four enclosures

Whether attending the Royal or Windsor Enclosure, make sure to get the dress code right