Earlier this week the British Prime Minister David Cameron attended the Lord Mayor’s Banquet at the Mansion House in the City of London. This annual event carries with it an evening dress code that is fast falling out of vogue: White Tie. A few weeks ago I wrote about Black Tie, which is basically a bastardised version of White Tie.

But this little worn, and to some people – little known, dress code has its rules, just like any other. It used to be the standard dress for evening dinners in the age of Downton Abbey, as indeed we see on the hit costume drama. Black Tie then came in (from America) and the aristocracy decided that it was a lot less hassle to wear every evening than White Tie.

Lord Grantham from Downton Abbey

Working from top to bottom, the gentleman should wear…

Bow tie The clue is in the title of the dress code – a white bow tie (hand-tied) is correct. Make sure your hands are spotless before tying as the brilliant white of the tie will show every mark unforgivingly

Shirt A white, winged collar (sometimes detachable from the dress shirt) should adorn the top of the dress shirt, which should be fastened with studs. I have white mother of pearl studs for such an occasion. Cuffs should be double-cuffed (i.e. cufflinks)

Jacket The black (sometimes midnight blue) tailcoat is double-breasted although never fastened and should just show a hint of the white waistcoat beneath

Decorations These may be worn if the invitation decrees – always on the wearer’s left lapel

Waistcoat This is white, made from a pique cotton and is fastened

Trousers Black and tapered with two pieces of braid running down the side of each leg (unlike Black Tie trousers, which should have just one). They should be held in place with the aid of braces, not a belt

Socks Long black silk evening socks are preferable, although merino wool is an acceptable modern alternative

Shoes Patent black and Oxford-style

Unlike with Black Tie where one sometimes sees people trying to inject colour in the outfit, one should not even contemplate such a solecism with this dress code.

Ladies have some rules to follow, although the design, patterns and materials of their gowns will change with the fashions of the age. Dresses should be sweeping and to the floor, but hair should not be. This should be restrained to avoid knocking out dancing partners. Long white gloves should be worn at all times, except when dining. Tiaras may be worn if the occasion warrants them.