<p>To get somebody's attention:</p>

<ul>
<li><p>If you need a moderator--just some moderator--flag a question, comment, or answer.</p></li>
<li><p>If you need a specific moderator, flag something relevant and in the "other" box of the flag dialog explain whom you are trying to reach (and why).</p></li>
<li><p>Add a comment to their question or answer.  (Please don't do this for just any question or answer: use a question or answer that is relevant to the reason for getting their attention.)</p></li>
<li><p>If they have participated in a comment thread, "ping" them using the "@" construct as illustrated in the question.  (NB: pinging does <em>not</em> work in questions, answers, nor in comments if the user has not already participated in that comment thread.)</p></li>
<li><p>If the user has participated in chat, you may ping them from that chat room.</p></li>
<li><p>If you have sufficient reputation, you may create a new chat room and invite users to join it.</p></li>
<li><p>Moderators may "super-ping" individuals from chat rooms: it works like a ping but does not require the individual ever to have been part of the chat before.  The mechanism to do this is a little intricate so it's not often done.</p></li>
<li><p>Moderators may contact users privately by e-mail.  Copies are automatically sent to the SE team and all other mods for the site: this is the mechanism used to address serious problems in usage or behavior.</p></li>
</ul>
