(NEXSTAR) – Just how comfortable do you make yourself on a flight?

Modern air travel can be hard enough – passengers have had to deal with a spike in ugly mid-flight incidents, additional charges for baggage and shrinking legroom.

Then there are the unspoken (and sometimes clearly spelled out) etiquette rules that some passengers ignore. A survey by online travel engine Skyscanner found that there are seven behaviors in particular that most offend passengers.

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7. Asking someone to switch seats

Nearly a third of respondents agreed that asking someone to leave the seat they reserved on the flight and swap places is a no-no. It’s not clear if this is situation-dependent for any of the respondents, but 31% of the 2,000 U.S. adults who were polled thought it was an offensive breach of flying etiquette.

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6. Using both armrests

An equal number of respondents found that fellow passengers who used both armrests were breaking an unspoken rule.

Some might disagree, saying it’s common knowledge that the person in the middle, who doesn’t have immediate access to the aisle and can’t rest on the wall of the cabin, gets both armrests as a type of consolation prize. An American Airlines captain fed up with rude in-flight behavior told all middle-seat passengers in a pre-flight address two months ago, “You own both armrests, that is my gift to you.”

Other etiquette experts disagree, however, and maintain that armrests on a plane should be considered common areas and therefore don’t belong to anyone.

“If there are extenuating etiquette circumstances, like a larger person in an adjacent seat, then the armrests aren’t yours,” said etiquette expert Nick Leighton, who hosts the “Were You Raised By Wolves?” podcast.

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5. Reclining your seat

An equal amount of flyers (31%) also have no sympathy for passengers who recline their seats during the flight.

Because the seat you pay to sit in often has the built-in ability to recline, it’s not surprising that people do it. With the tight seating dimensions, especially in economy, reclining one’s seat has become a divisive topic.

One widely publicized incident aboard an American Airlines flight was caught on video after a woman says the man behind her, furious that she reclined her seat, began punching the back of her chair repeatedly. The woman, Wendi Williams, a teacher from Virginia Beach, has since deleted video of the incident, which was viewed hundreds of thousands of times.

Whether you align with the recliners of the world or not, etiquette experts suggest asking the person behind you if it’s OK to recline before doing so to maintain friendly relations during the flight.

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4. Taking off shoes or socks

Another hot button etiquette decision involves passengers’ feet. Do you remove your shoes – or your shoes and socks – on the plane? Thirty-five percent of respondents said ditching the footwear was one of the “most offensive” airplane etiquette breaches.

While the survey includes both sock-clad and barefoot flyers, some would draw a distinction between those two camps.

“Shoes off, acceptable,” wrote one person on Reddit. “Socks off, you’re a savage who doesn’t belong in polite society.”

More importantly, airlines themselves draw a line between the two. Airlines have carriage documents that lay out the terms and conditions passengers are subject to when they take a flight. United, for instance, reserves the right to remove passengers “who are barefoot” or have a “malodorous condition.”

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3. Talking to strangers, being a chatty seatmate

Nearly four in 10 respondents (39%) find striking up conversations with strangers on the airplane and being “chatty” during the flight offensive.

This may sound harsh to some of the more outgoing, friendly flyers, but there’s maybe no faster way to burst any illusion of private space on a crowded airplane than striking up a conversation with someone who just wants to sit in silence.

If you find yourself on the receiving end of such a conversation, Diane Gottsman, founder of The Protocol School of Texas, told The Points Guy that “subtle signs like [putting] headphones on signal to other travelers that you are hoping to have some alone time.”

Sleep masks, sunglasses and even the hood of a sweatshirt can also be used to subtly deliver the message.

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2. Using the speakerphone

What’s worse than being forced to listen to someone talking on the phone while on an airplane? Being forced to listen to both sides of the conversation.

Over 40 percent of those surveyed agreed that declining to use headphones and subjecting the rest of the plane to a speakerphone or video call was one of the most offensive etiquette fails on an airplane.

The same American Airlines captain who broke out his best dad voice on passengers over the summer had some words for speakerphone fans.

“The social experiment of listening to videos on speaker mode and talking on a cellphone in speaker mode, that is over,” he said. “Over and done in this country. Nobody wants to hear your video. I know you think it’s super sweet. It probably is, but it’s your business, right? So keep it to yourself. Use your AirPods, use your headphones, whatever it is. That’s your business, okay? It’s just part of being in a respectful society.”

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1. Personal grooming

Coming in first at 42%, the most offensive lack of etiquette on an airplane, survey-takers said, was personal grooming, including painting nails, clipping nails, trimming beards and more.

A former flight attendant’s popular social media channels document what she finds to be some of the worst passenger behaviors – and lets just say that bare feet, along with nail clipping/filing, is a theme.

“Please do not file your nails on the plane!! I was sitting beside a lady who filed her nails for the whole flight and her fingernail dust was all over me,” one person wrote in a Reddit “social skills” forum.

There have been highly publicized incidents in the past that did not turn out well for the in-flight groomer.

A Los Angeles-area woman was detained for 10 hours after her nail painting led to an altercation with a Southwest Airlines flight attendant.

Gottsman had this to say to The Points Guy when it comes to personal grooming on an airplane: “Grooming is seldom an emergency. Using your water glass to brush your teeth and then spitting the water back into the cup is over the line … do not clean your ears, use your battery-operated razor or apply sunless tanner in the cabin of an airplane. You are not at home, and this is not your personal lavatory. Less is best.”