In the rich text editor:
@cometgun
In a comment:
[cometgun](https://chowlings.com/user/cometgun)
For Names and Avatars:
In the rich text editor:
%cometgun
In a comment:
[![cometgun's Avatar](https://chowlings.com/images/avatars/1189.jpg?v=1644063257)](https://chowlings.com/user/cometgun) [cometgun](https://chowlings.com/user/cometgun)