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