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