“Ping” means to direct a post to a particular user, who may not be active on a given thread, to alert that user to something he or she may be interested in.
So, if I know that user “abcxyz” works in a medical field, I might ping abcxyz on a thread on which some medical topic is under discussion.
Some people ping themselves as a way of bookmarking a thread.
The term comes from the sonar world.
Got it!! Thanks for that.. I understand it now, I don’t know how to do it but I don’t think I would ever use it. It was buggin me though that’s for sure!