In the rich text editor:
@kingxson
In a comment:
[kingxson](https://chowlings.com/user/kingxson)
For Names and Avatars:
In the rich text editor:
%kingxson
In a comment:
[![kingxson's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/kingxson) [kingxson](https://chowlings.com/user/kingxson)