It's hard to believe the punk-themed Met Ball happened almost a year ago. Kim Kardashian's Givenchy floral dress with built-in gloves is still so vivid in our mind's eye, it could have been yesterday.

But if you're one of the New York super-rich, you'll know that the invitations to the 2014 Met Ball went out yesterday. It's time, then, to forget about the punk misadventures of last year and get our heads around this year's event, to be held on 5 May in honour of the Charles James: Beyond Fashion exhibition at the Metropolitan Museum of Art.

The dress code is 'White tie and decorations'. Pity those who have been invited and will now be wondering what the hell it means; we all know the angst induced by the dress codes at your friends' weddings (what the hell is bohemian black tie, anyway?), and at least on those occasions you know that Anna Wintour won't be there.

Luckily, we can help with this one. Below, a primer to assist anyone invited to the 2014 Met Ball.

Who is Charles James? 
An English designer, born in 1906, who became famous as one of America's first couturiers. He was known particularly for his work in the 1940s and 1950s – he specialised in sculptural dresses, expertly and elaborately engineered with multiple layers. The effect was graceful and light as air. Cristobal Balenciaga once referred to James as 'the world's best and only dressmaker', while Christian Dior described his work as 'poetry'.

What should female guests wear? 
An elegant, full-skirted sweeping gown should do the trick. 

So what on earth does 'white tie and decorations' mean?
This bit is all about the men, who should dress in traditional white tie. According to WWD that means a black tailcoat, a waistcoat, a wing collar shirt and a white bow tie. 'Decorations' refers not to Christmas baubles but to military decorations – medals, for those who've got them, and failing that it's time to use your initiative. WWD suggests 'lapel pins' and 'more creative flights of fancy'.

We can't wait to see how Kanye interprets it.

Since there's still a month to go, amuse yourself by revisiting the best and worst of last year's efforts.