@MartinSleziak I voted to close as a dupe. But why ping a user's post from roughly 490 days ago? Just confuses the rest rest of us. Better that you did comment below the question. Having done that, your reference to the author there is sufficient.
@amWhy I am pretty sure you know that - but if a user wasn't in a chatroom for some time they aren't pingable just by writing @username. So this is just a way to ping the spceific user in chat.
Pinging the user in chat seemed to me a better option than leaving a comment which would need deleting later.
@MartinSleziak No need for snark. In any case, had you included such context for all relevant users in this chat, I would have had no issue and would not have commented.
When people abandon the site, they're not here to object, and if you'll only act when they reply to your comments, six years later, you'll end up doing nothing.
@MartinSleziak Yes, I think so, and I have thus voted to close as a dupe.