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