Nope I don't think he means the follower system.What he mean is,he needs to have a notification sent to him if a members tags his user-name in a post.Similar to telegram/facebook.I'm not sure if this is discussed somewhere but considering the new website (if ever launched) will have the notification system,this wouldn't be a big feature to add.
Ahh, I see... For some reason I thought he meant something like "adding a tag to the user", and not literally tagging him in a post.
IIRC, this feature is already available in the new beta software (which is unavailable right now for some reason).
Sorry @shield132