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