Just because you’ve mastered the art of not looking like an uncultured, uncouth slob in your country doesn’t mean those skills translate to the rest of the world. In fact, many things considered innocuous or even polite where you’re from might raise (or sternly lower) eyebrows in other parts of the world. With that in mind, here are 11 behaviors that are widely viewed as acceptable in the United States but considered rude in other corners of the globe.

1. Tipping

In the U.S., not tipping is the easiest way to become the least popular person at any restaurant or bar, equally hated by friends, significant others, servers, and restaurant owners alike. But in Japan, tipping at restaurants is actually considered rude—superior service is expected without an added incentive and is calculated into the bill. Considering tipping has little to do with good service, and that it makes servers’ ability to make a living wage completely reliant on the kindness of customers, it might be one custom worth ditching within American borders [PDF]. But don’t totally skimp on the tips if you’re traveling in Japan. In services like tourism, where guides are primarily interacting with Westerners, the practice has caught on a bit.

2. Whistling

In the United States, whistling is as open to interpretation as half a glass of water: positive types associate it with a carefree, can-do attitude, while cynics associate it with cloying levels of chutzpah and deficient levels of self-awareness—but you’d be hard-pressed to find many folks who consider it rude. But this isn’t the case in Haiti, especially for kids, who are generally to be seen and not heard. According to Haitian Creole language blogger Mandaly Claude Louis-Charles, whistling exists alongside sitting cross-legged, making direct eye contact, and standing with your hands on your sides as things to never be done near elders.

3. Open-mouth Laughing

Americans, in general, tend to laugh freely and loudly. Of course, people all around the world like a joke, but it doesn’t always follow that exploding into hysterical, open-mouth laughter is a desired, or even polite response. In Japan, open-mouthed, teeth-exposed laughter is thought to “sound like horses,” and is considered impolite, and in particular, unladylike, in the same manner Americans consider coughing, yawning or eating with your mouth open to be rude.

See Also: 14 Dining-Related Taboos from Around the World

4. Showing Up On Time

While most Americans are fine with people showing up fashionably late to certain kinds of parties and events, it’s generally considered bad form to keep folks waiting, particularly if the events of the night are time-sensitive. Take, for instance, a dinner party where there’s a lot of preparation involved and showing up late means potentially delaying the meal. In Argentine culture, however, showing up for a dinner party right on the nose would be like showing up roughly an hour early in America: it’d be considered slightly audacious, and you’d risk finding your host still in the throes of preparation. This consistently lax sense of timekeeping, largely inherited from Spanish culture, extends to many corners of Argentine culture.

5. Going Sans-mask While Sick

If you live in a major metropolitan area, there’s a good chance you’ve seen a Japanese person sporting a surgical mask, even if they’re, say, wearing business attire and probably not fresh out of surgery. In the United States, a lot of people see this as a bit silly, but you should thank those mask-wearers—it’s generally a common courtesy for people who feel like they’re coming down with something and don’t want to spread their germs. It makes sense, considering Japan is one the most densely-populated and urban large countries on earth.

Interestingly, since the early ‘00s, masks have also caught on in Japan for a wide range of reasons beyond shielding germs, including: staying warm, hiding emotional reactions, and just looking generally fashionable.

6. Opening a Gift in the Presence of the Giver

This might seem like an odd one, since in America seeing a gift-opener's sincere appreciation/half-hearted attempts to disguise their disappointment is pretty much the best part of gift giving. But in many Asian countries, including China and India, tearing right into a present in front of the gift-presenter is considered very poor form, both because if one gift-giver has clearly out-gifted someone else, it’s a bit awkward, and because digging right in looks a bit greedy and lacks suspense.

See Also: 8 German Travel Tips for Visiting America

7. Not Rejecting a Gift

The social politics of gift-giving around the world and throughout history is surprisingly complex and laden with opportunities for missteps, so here’s another tip to keep in mind in case you’re ever traveling through Asia and feeling super generous. In the United States, having someone reject a gift up to three times might look a bit overly modest at best, and a bit rude at worst. However, in much of Japan it’s par for the course—according to blogger Makiko Itoh, it's “a ritualistic dance" of manners and tradition.

8. Doing Pretty Much Anything Left-handed

Sure, in America shaking hands is universally reserved for the right hand. But in almost every other facet of life, while being left-dominant may mean suffering hundreds of minor inconveniences on a daily basis, it doesn't make it look like it’s your life’s work to insult everyone, all the time. Here are just a few things that, in many parts of the world, aren’t to be done with the left hand: give gifts, receive gifts, touch people—just about anything and everything that involves contact and doesn’t require two paws.

Why? If your first instinct is to think the left hand is associated with evil, you aren’t wrong; there are myths about the left hand and lefties being sinister across many, many cultures. But the primary reason is much more practical: throughout history, and still in many countries throughout the world, the left hand is reserved for the nittiest and grittiest of bathroom duties.

9. Blowing Your Nose in Public

This one isn’t as counterintuitive as a lot of the other entries on the list. The bathroom is reserved for almost every activity that involves getting something in or on your body out or off of it, but in America, nose-blowing in public is considered a minor annoyance rather than a no-no, the way it’s viewed in Japan. In fact, the Japanese word for nasal discharge, hanakuso, literally means “nose waste.”

10. Crossing Your Fingers

Sure, this isn’t exactly an everyday occurrence in America, but if you spot someone crossing their fingers, chances are they’re wishing themselves or someone else the best of luck and wishes. But if you happen to have already binge-watched Netflix’s Unbreakable Kimmy Schmidt, you probably know that crossed fingers carries a very different connotation in Vietnam: a quick, crude and impolite shorthand for “vagina.”

See Also: Tongue Rolling and 5 Other Oversimplified Genetic Traits

11. Putting Your Hands in Your Pocket While Speaking

What’s considered a go-to move for socially awkward guys and gals throughout American is actually considered disrespectful in quite a few countries. Just ask Bill Gates, who found himself in the middle of a minor international controversy after shaking South Korean president Park Geun-hye’s hand with his left hand firmly planted in his pocket. Many South Koreans were—unlike Gates—up in arms about the gesture, but Gates, who, according to the gaming website Kokatu is "a long-time, serial hand-in-pocket shaker," surely meant no harm. Lest we forget, he started off as a socially awkward American guy himself once upon a time.