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