title: iOS 10 "Starting WebFilter logging for process" + Proxy-Authorization header removed from request
body: <p>Starting from iOS 10 I noticed such logs in my app</p>
  
  <pre><code>yyyy-MM-dd HH:mm:sss HelloWorld[XXX:XXXXXX] WF: === Starting WebFilter logging for process HelloWorld
  yyyy-MM-dd HH:mm:sss HelloWorld[XXX:XXXXXX] WF: _userSettingsForUser mobile: {
      filterBlacklist =     (
      );
      filterWhitelist =     (
      );
      restrictWeb = 1;
      useContentFilter = 0;
      useContentFilterOverrides = 0;
      whitelistEnabled = 0;
  }
  yyyy-MM-dd HH:mm:sss HelloWorld[XXX:XXXXXX] WF: _WebFilterIsActive returning: NO
  </code></pre>
  
  <p>I have reviewed <a href="https://developer.apple.com/library/content/releasenotes/General/WhatsNewIniOS/Articles/iOS10.html">iOS 10 Release notes</a> but there is no info about WebFilter feature</p>
  
  <p>Also I noticed that for some sites <code>Proxy-Authorization</code> removed from request (I use programmatically configured proxy) and this issue started from iOS 10.</p>
  
  <p>Anybody can throw a light on this?</p>
  
  <p><strong>Update 1</strong></p>
  
  <p>I found stable case when this happens</p>
  
  <ol>
  <li>WebView request <code>/</code> for some site <code>example.org</code> over <code>https</code></li>
  <li>Received <code>html</code> contains <code>http</code> link to some resource (image for css) like <code>http://example.org/icon.png</code></li>
  <li>This lead to Header removal </li>
  </ol>