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