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