After rotating XD 90 to the right, it looks like a smile.
The main purpose of emoji is to express a person's mood, so it is accepted in general forums. However, there are still some usage norms, such as: there are no words in the title, which may be listed as prohibited Martian words in some serious discussion forums; To show solemnity. However, Martians do not contain emoticons, and emoticons are not equal to Martians, so we should pay attention to their relationship.
Extended data:
Emotion (emotional icon) is characterized by making some very simple facial patterns on a computer (formerly a typewriter) with punctuation marks and English words. The most commonly used words are:-) for smiling and:-(for unhappy. XD, which stands for smile, is also very popular (this is also the most commonly used American word in Hong Kong). Other common ones are: -o (surprise) and: -p (sticking out your tongue, that is, joking). Because the accommodating part of speech is an incomplete expression that falls to the left.
What Japanese fans now call "Yan Zi" generally refers to Japanese Yan Zi or Japanese Yan Zi, which is popular in Japanese culture. Japanese Chinese character is called "Yanzi", and the word "Yanzi" stands for face. The meaning of the word "Yan Zi" actually refers to using different words or characters to express the author's mood.
Baidu Encyclopedia-Yan Wen Zi