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