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