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