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