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