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