In the rich text editor:
@sam_bam_artv2
In a comment:
[sam_bam_artv2](https://cometcrashers.org/user/sam_bam_artv2)
For Names and Avatars:
In the rich text editor:
%sam_bam_artv2
In a comment:
[](https://cometcrashers.org/user/sam_bam_artv2) [sam_bam_artv2](https://cometcrashers.org/user/sam_bam_artv2)