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