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