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