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