In the rich text editor:
@SomeRandomTaco
In a comment:
[SomeRandomTaco](https://www.whistlercrest.com/user/SomeRandomTaco)
For Names and Avatars:
In the rich text editor:
%SomeRandomTaco
In a comment:
[](https://www.whistlercrest.com/user/SomeRandomTaco) [SomeRandomTaco](https://www.whistlercrest.com/user/SomeRandomTaco)