Each winter, more and more people take the plunge and decide to invest in swanky winter coats. It’s a smart decision — a well-made winter coat can last years provided you take care of it, and they don’t tend to fall victim to the same fashion trend cycles as other items of clothing. Unfortunately, some newbies to the wide world of winter coats don’t know one crucial thing about their new possessions.

@maceyphall Respectfully, I’m begging you. #fyp #nyc #lifehacks #winter #winterfashion #fashion #fashiontips ♬ ABBA X Elton John X Frank Ocean TWINSICK MASHUP - TWINSICK

As TikToker Macey Hall demonstrated in this video, many people with new winter coats haven’t realized yet that you need to cut the vent, or tacking, stitch at the back of the coat before wearing it. If you have no idea what I mean, just watch the video, or watch this next one featuring a more in-depth explanation about what the stitch is and why you should cut it.

@witchbitchthrifttok Are you guilty of this too? #fashionhack #witchbitchthrift #winterfashion ♬ Cena Engraçada e Inusitada de 3 Minutos - HarmonicoHCO

Essentially, the stitch is only there for packaging purposes (as one commenter helpfully explained, it keeps the coat flat and less wrinkled in transit and on hangers), and while leaving it as is isn’t a horrific crime, cutting it does give you a wider range of motion when wearing the coat. It also just looks better once it’s cut.

Thanks to this video, we have now learned that some people feel incredibly strongly about cutting vent stitches. One commenter had an encounter with such a person, writing, “My first day at my first internship some woman just grabbed my skirt in the elevator and cut my vent stitches without even warning .”

Yikes! But that anecdote serves as a good reminder that vent stitches aren’t just found on coats, but on other garments like skirts and suits as well.

Some people have very good reasons for not knowing about this requirement — those in the tropics, for example, as a commenter reminded us when they commented, “I’m too close to the equator to understand this.” Others revealed that they don’t cut their vent stitches because they’re planning on returning the coat, in which case, more power to you.