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