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