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