WORN with pride and swallie-fuelled swagger, the kilt has become an integral part of Scotland’s often confused and regularly contested identity. Look hard enough, and you’ll probably find the usual guff about ancient Greece or wherever, but it’s about as unsullied Scottish as you’ll find.

Official histories often give the kilt a 16th century origin, which sounds surprisingly late (perhaps the Highlands were just coming to wider attention). As for the word, it is Scots – though sometimes said to derive from Old Norse kjalta – and is something to do with tucking clothes up around your torso, as you do.

So, what is a kilt? You’re kidding me, right? All right, here are a few technicalities, most of them doubtless inaccurate. It’s a garment – agreed? – with overlapping aprons at the front and pleats at the back. Made today of woven worsted wool, a long plaid might be six to eight yards long and a short one two to four yards (there are strict rules about such things and so no two prescriptions are the same).

Today, the full-length plaid, wrapped up and over the shoulder, is usually only worn by pipe bands. Warriors used to discard it before charging into battle in heavily pleated or quilted knee-length shirts. Bit of a hassle if the enemy charged when you were getting changed.

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By the late 17th or early 18th century, the small kilt (fèileadh beag), mòr or less the lower half of the feileadh mòr, came into use and is the usual version worn by punters today. After Culloden, the English-British government outlawed Highland dress including kilts, but an exception was made for Highland regiments, and the kilt also remained popular with international romantics who viewed Highlanders as noble savages

Tartan: much palaver about this, of course. Though recorded being worn by Celtic warriors in Roman times, it was only in Victorian times that a link with clan surnames was formalised, mainly as a selling point. Before then, association with patterns – technically known as “setts” – was usually regional.

Today, you can probably find a McBlenkinsop tartan, and there are also tartans for districts, societies, companies, and football clubs.

You’ll look a fool if you don’t wear a sporran with your kilt. Coming from the Gaelic for “purse”, it’s a functional accoutrement in which one might secret a small flagon of Buckie during ordeals such as weddings.

Traditionally, at least in the post-medieval era, they’d be made of white goat hair, which was largely superseded by seal skin or various forms of leather. Today, you can get vegan ones of faux leather or fur, which upsets the toffs often involved in codifying the pantomime aspect of kilts.

The Herald: Sam HeughanSam Heughan

Now, unusually for this column, we are forced to talk pants. Yes. Fnaar-fnaar. Let’s do the jokes first. Is anything worn under your kilt, my dear man? No, madam, it’s all in working order. More facetiously: [Snigger, snigger] What do you wear under your kilt, Jocko? Your maw’s lipstick, pal.

So, what lies beneath? The Scottish Tartans Authority (STA) hit the headlines when it reportedly said “going commando” was childish, unhygienic and flew in the face of decency. It didn’t quite say that, but it wasn’t far off: it has clarified that going pants-free could conceivably be any of these things in the wrong hands, as it were.

The gist seems to be that it’s not a good idea to go commando if dancing or lifting your knees for any peculiar reason. Indeed, for the majority of occasions, the STA said kilt-wearers should consider wearing what they do under their trousers, stockings and suspenders not included.

More problems arose with the advent of kilt hire and the unhygienic state of some garments returned by those eschewing pants. For that reason, in 2004, McCalls, one of Scotland’s oldest kilt-hire companies, insisted underwear be worn at all times and described the supposed tradition as “silly”.

The move provoked outrage. Sir Jamie McGrigor, then the Scottish Conservatives’ culture spokesman, said it was “absolute nonsense”, and ruined the “romance and mystique” of a true Scotsman’s nether regions. However, he has also admitted midges could be a problem.

Alex Salmond, then a big wheel in the SNP, said the rule would be impossible to enforce: “Are they going to employ an army of Y-front spotters?”

Alas, Y-front spotters are fairly common among the female population, particularly on hen nights. In 2015, barmen at the Hootenanny pub, Inverness, stopped wearing their kilts after getting fed up with drunken lassies lifting them.

These latter might have taken a lesson from sergeant-majors in Highland regiments of the British Army, where going commando is compulsory and mirrors on sticks are used to look up things.

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What about the other sartorial guff surrounding kilts? Well, “hose”, socks to you and me, are often white, which is scorned by purists who say they should match the kilt. But that never looks right. Thick cream always works. Dark socks enhance the pallor of the Scottish knee. Diced or Argyll patterns should be illegal.

As for the shirt and jacket traditionally worn at functions, suffice to say, it’s as if someone decreed: “And we’ll add this English dinner party crap to the top.” I do, however, approve of wearing a big belt with a muckle buckle and maybe even a sgian dubh as a reminder that, after dinner, Scots often treacherously kill their hosts.

As for footwear, providing you’ve got the calves for it, a kilt looks best with Doc Marten and thick socks rolled down. But, forced into wearing a kilt, most of us ensure the socks are long enough one way and the kilt long enough the other so that barley an inch of pallid flesh might be seen.

We look more like men dressed as 1950s female librarians. Still, it’s not given to all of us to look as good as Sam Heughan (Outlander, Men in Kilts). And we don’t generally get bothered by boozy women or dubious military men with mirrors on sticks.