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