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