What they are, how many you should have in your jacket and jeans and what to put in them other than your hands.

Pockets. They’re fairly self-explanatory, right? Wrong. While these little fabric compartments all fulfil the same general purpose – namely, carrying things you’d otherwise have to hold in your hands – they vary vastly in form, function and formality. We’d hate for you to come a cropper in conversation with your tailor, which is why the MR PORTER team has put together this handy primer on all things pockets.

(From most formal to least formal)

**The jetted pocket **

Appearing from the outside as nothing more than a slit bordered by two thin strips of fabric or “welts”, the jetted pocket is the neatest and most formal pocket you’ll find on a jacket. In the case of a tuxedo, it’s not uncommon to see these pockets finished with welts in a different fabric, such as satin.

The flap pocket

A flap pocket is usually nothing more than a jetted pocket (see above) with a flap of fabric stitched to the upper welt. Simple, right? The flap is designed to keep the contents of your pocket secure, but it does rather interrupt the silhouette, and so it’s traditionally thought of as slightly less formal than a standard jetted pocket. You can tuck the flaps inside the pocket for a more streamlined look.

The patch pocket

From a tailoring perspective, the patch pocket is as straightforward as it gets. Just take a piece of cloth and sew it onto the garment – leaving the top unstitched, of course – et voilà, you now have yourself a patch pocket. It’s the kind of pocket you see on gold-buttoned naval blazers and the unstructured jackets that Italians wear in summer. Casual, in other words.

The patch-flap pocket

Still reading? If you’ve made it this far, you’ll have no problem understanding what a patch-flap pocket is, but for the sake of absolute clarity it’s a patch pocket with a flap attached. (Actually, it’s not quite that simple. The flap is often secured with a button.) Here, we leave tailoring behind and venture into the realms of utilitarian outerwear. This kind of pocket is typically found on safari jackets and waxed-cotton biker jackets (think Belstaff).

The cargo pocket

Constructed with a pleat, the cargo pocket is a modified patch pocket that is designed to expand, much like a set of bellows. Hence its alternative name, the bellows pocket. It was first designed for soldiers in the field, but has since filtered down into the casual male wardrobe, where it can be found on field jackets, cargo trousers and so on.

The watch pocket

That curious miniature pocket tucked inside the front-right pocket on a pair of jeans? It’s a watch pocket, according to Levi Strauss. Invented in 1873 to store pocket watches before the advent of the wristwatch, it has since been used to hold everything from matches and coins to condoms.

The ticket pocket

The ticket pocket originates with the early rail commuters of Victorian Britain, who looked to their tailors for a convenient place to store their tickets and loose change while travelling between the countryside and the city. Sitting just above the right hip pocket, this extra pocket traditionally denotes a less formal jacket.

01. Less is more

Traditionally, the fewer pockets your jacket has, the smarter it is. A tuxedo, the height of formality, will have no more than three external pockets: one jetted pocket on each hip and one on the left chest. A sports jacket might have an additional ticket pocket, and a field jacket will have an added pocket on the right chest. Long story short, the more pockets your jacket has, the more you look as if you’re off to spend a weekend in the countryside.

02. In stitches

What’s with those stitches? If you’ve ever bought an off-the-peg blazer, you might have wondered why the hip and chest pockets are sewn shut. It’s not unreasonable to assume that this is a sign that the pockets are merely decorative and not intended for use, but the truth of the matter is that these are merely temporary stitches put in place to stop people from damaging the pockets while trying on a jacket before purchase. Once you own the jacket, feel free to cut them out.

03. Get stuffed

What good is a pocket if you can’t use it? While there’s certainly some truth to this argument, it’s worth remembering that an overstuffed pocket can ruin the carefully constructed shape of a jacket. This is especially true in the case of a stiffly tailored jacket with a suppressed waist, the lines of which will struggle to conceal a bulky billfold wallet. Our suggestion? Opt for a cardholder and keep your larger belongings in a clutch or tote.