In the rich text editor:
@pkio
In a comment:
[pkio](https://chowlings.com/user/pkio)
For Names and Avatars:
In the rich text editor:
%pkio
In a comment:
[![pkio's Avatar](https://chowlings.com/images/avatars/465.png?v=1644063295)](https://chowlings.com/user/pkio) [pkio](https://chowlings.com/user/pkio)