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