field is a bitmask. The following
bits are assigned:</p>
<blockquote>
<ul class="simple">
<li>1 = <a class="reference internal" href="#authentication">authentication</a>.</li>
<li>2 = <a class="reference internal" href="#request-string">request string</a>.</li>
</ul>
</blockquote>
<p>If multiple bits are present in the extension field, the extension
bodies are appended to the packet in the order of least significant
bit first. For instance, if both bit 1 and 2 are set, the extension
represented by bit 1 com