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