Revision 1136419 of Tk

<div>{{HTTPSidebar}}</div>

<p>The <strong><code>Tk</code></strong> response header indicates the tracking status that applied to the corresponding request.</p>

<table class="properties">
 <tbody>
  <tr>
   <th scope="row">Header type</th>
   <td>{{Glossary("Response header")}}</td>
  </tr>
  <tr>
   <th scope="row">{{Glossary("Forbidden header name")}}</th>
   <td>no</td>
  </tr>
 </tbody>
</table>

<h2 id="Syntax">Syntax</h2>

<pre class="syntaxbox">
Tk: !  (under construction)
Tk: ?  (dynamic)
Tk: G  (gateway or multiple parties)
Tk: N  (not tracking)
Tk: T  (tracking)
Tk: C  (tracking with consent)
Tk: P  (potential consent)
Tk: D  (disregarding DNT)
Tk: U  (updated)
</pre>

<h2 id="Directives">Directives</h2>

<dl>
 <dt>!</dt>
 <dd>Under construction. The origin server is currently testing its communication of tracking status.</dd>
 <dt>?</dt>
 <dd>Dynamic. The origin server needs more information to determine tracking status.</dd>
 <dt>G</dt>
 <dd>Gateway or multiple parties. The server is acting as a gateway to an exchange involving multiple parties.</dd>
 <dt>N</dt>
 <dd>Not tracking.</dd>
 <dt>T</dt>
 <dd>Tracking.</dd>
 <dt>C</dt>
 <dd>Tracking with consent. The origin server believes it has received prior consent for tracking this user, user agent, or device.</dd>
 <dt>P</dt>
 <dd>Potential consent. The origin server does not know, in real-time, whether it has received prior consent for tracking this user, user agent, or device, but promises not to use or share any <code>DNT:1</code> data until such consent has been determined, and further promises to delete or permanently de-identify within 48 hours any <code>DNT:1</code> data received for which such consent has not been received.</dd>
 <dt>D</dt>
 <dd>Disregarding DNT. The origin server is unable or unwilling to respect a tracking preference received from the requesting user agent.</dd>
 <dt>U</dt>
 <dd>Updated. The request resulted in a potential change to the tracking status applicable to this user, user agent, or device.</dd>
</dl>

<h2 id="Examples">Examples</h2>

<p>A <code>Tk</code> header for a resource that claims not to be tracking would look like:</p>

<pre>
Tk: N</pre>

<h2 id="Specifications">Specifications</h2>

<table class="standard-table">
 <tbody>
  <tr>
   <th scope="col">Specification</th>
   <th scope="col">Status</th>
   <th scope="col">Comment</th>
  </tr>
  <tr>
   <td>{{SpecName('Tracking','#Tk-header-defn', 'Tk header field')}}</td>
   <td>{{Spec2("Tracking")}}</td>
   <td>Initial definition.</td>
  </tr>
 </tbody>
</table>

<h2 id="See_also">See also</h2>

<ul>
 <li>{{HTTPHeader("DNT")}} header</li>
 <li>{{domxref("Navigator.doNotTrack")}}</li>
</ul>