This is quite weird since slack generally encourages people to use their real names for exactly this reason. In slack, tagging someone has a few added benefits

This is quite weird since slack generally encourages people to use their real names for exactly this reason. In slack, tagging someone has a few added benefits, even in a private convo. In a DM, if I tell you @fred can help you if you have any questions, you can now hover to see Fred's availability status, and click to message them. An added benefit is that these tags track the user's displayed name. If Fred changes their name to Francine, the places where you've tagged Francine in the past will update automatically. You can also search for places where users are mentioned this same way.