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