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