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