In the rich text editor:
@WhistleCake
In a comment:
[WhistleCake](https://chowlings.com/user/WhistleCake)
For Names and Avatars:
In the rich text editor:
%WhistleCake
In a comment:
[![WhistleCake's Avatar](https://chowlings.com/images/avatars/2264.png?v=1682650968)](https://chowlings.com/user/WhistleCake) [WhistleCake](https://chowlings.com/user/WhistleCake)