In the rich text editor:
@prahmor
In a comment:
[prahmor](https://www.chowlings.com/user/prahmor)
For Names and Avatars:
In the rich text editor:
%prahmor
In a comment:
[](https://www.chowlings.com/user/prahmor) [prahmor](https://www.chowlings.com/user/prahmor)