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