This article originally appeared on ABACUS Sending an ordinary smiley face like 🙂 to your WeChat friend in China seems simple enough… but your friend might give you a strange look for it. (Perhaps a real-life version of 🤔.) Turns out that the country’s most popular social app has its own etiquette for using emoji. WeChat, the app that does everything Consider 👋. It looks a little different in WeChat's version but at least it's not a biscuit . For many of us, this would simply mean that we’re happily waving goodbye. In WeChat, it could mean that you just said something really dumb and the sender doesn’t want to speak to you. Ouch! And as for the regular smiley face? That’s not for friends. That’s usually reserved for your boss. The WeChat Annual Data Report 2018 shows that emoji use doesn’t differ purely by geography, but also by the generation that uses them. The report -- full of interesting numbers on the only Chinese app with 1 billion users -- analyzed which groups of users prefer which emoji, along with their daily habits (leaving some users wondering who stole their chat records). For instance, those born after the year 2000 preferred to use the facepalm emoji 🤦♀️. According to the report, this generation gets little sleep: They go to bed late and get up early, kind of what we would expect from overburdened Chinese school kids. (Incidentally, the data also reveals that the post-2000 generation has a sweet tooth: WeChat Pay says the number of young people who pay for cold drinks and desserts has gone up by 230% since last year.) As for the generation born in the 1990s, their favorite emoji is an old classic: 😂, or face with tears of joy. This emoji has fans internationally -- it was the Oxford Dictionary Word of the Year in 2015. WeChat says this generation is known to get out of bed pretty late and use public transportation quite often. There’s one emoji you can’t see in China Those born in the 1980s read content related to national news and their favorite emoji is 😁, the beaming face with smiling eyes. The 1970s generation apparently loves to snicker because they usually use 🤭, the face with hand over mouth. This generation is also fond of browsing through their WeChat Moments, a function similar to Facebook’s wall. Finally, those over the age of 55 really like the... Like. We mean this 👍, not the Facebook button. Some emoji are exclusive to WeChat, and have unique meanings. For instance, take the nose-picking one. That doesn’t mean you’ve got this thing in your nose you really need to get out… it means you’ve just heard or seen something really dumb. Other emoji are related to Asian culture. For instance, it’s polite to act a little embarrassed when asking for a favor, so the wide-eyed emoji is perfect when you’re asking your boss for some vacation days. (If only that emoji existed here, so I can ask my boss for extra vacation days…) Someone trademarked a popular WeChat emoji and netizens are mad For more insights into China tech, sign up for our tech newsletters , subscribe to our Inside China Tech podcast , and download the comprehensive 2019 China Internet Report . Also roam China Tech City , an award-winning interactive digital map at our sister site Abacus .