I'm reading a novel. What does the OP mean by 'att'?

Answer 1

Atting was usually used in web novels to indicate the act of sending a private message or a private message to a character. In the plot of the novel, the author would sometimes use "@" to express special attention or instructions to a certain character, such as asking the reader to use a specific reply format or content when replying to a character's private message. Therefore, it was usually used to indicate the order or attention of a certain character.