If I add a comment, then realise I've forgotten to add the @fred to ping a user I can either:
edit my comment and put in the @fred
delete the comment and retype it with the @fred
Does Fred get pinged in both cases? Specifically, in case (1) if I edit an existing comment and add the @fred does that cause Fred to be pinged when I save the changes?
I suppose there's a corollary: if I edit the comment as many times as I can in the 5 minutes allowed can I generate multiple pings and really annoy Fred?