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