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