What do the letters used by players in World of Warcraft when chatting mean?

Some of them are shorthand, such as thx for thank you, and some for expression, such as! Oh! , which means happy! There are many more, some of which represent replication, for example, STSM, which is the Stansom replication of the Eastern Plague! Ask the people in the game if you don't understand. The quality of China players is also very high, and they will be very enthusiastic to help you answer!