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