In the rich text editor:
@DeathRat24
In a comment:
[DeathRat24](https://chowlings.com/user/DeathRat24)
For Names and Avatars:
In the rich text editor:
%DeathRat24
In a comment:
[![DeathRat24's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/DeathRat24) [DeathRat24](https://chowlings.com/user/DeathRat24)