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