character.</li>
<li><code class="code">@</code>: take no argument and output one <code class="code">@</code> character.</li>
<li><code class="code">,</code>: take no argument and output nothing: a no-op delimiter for
     conversion specifications.</li>
</ul>

   The optional <code class="code">flags</code> are:<ul>
<li><code class="code">-</code>: left-justify the output (default is right justification).</li>
<li><code class="code">0</code>: for numerical conversions, pad with zeroes instead of spaces.</li