In the rich text editor:
@nauticul
In a comment:
[nauticul](https://chowlings.com/user/nauticul)
For Names and Avatars:
In the rich text editor:
%nauticul
In a comment:
[![nauticul's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/nauticul) [nauticul](https://chowlings.com/user/nauticul)