If a user comments on their own post and there is only one person who has previously commented, then that person should be notified when the author comments even if '@user' is not specified
courtesy to Benjol from my closed question Notifications for comments of others posts
@user
to the new comment, so that you can delete it if it is not appropriate.@user
syntax?@
-reply is needed and when it isn't. I am not thrilled with htis.