title: Why HSHELL_WINDOWDESTROYED, HSHELL_WINDOWCREATED?
body: <p>MSDN - "<code>ShellProc</code> Function", "<code>RegisterShellHookWindow</code> Function":</p>
  
  <pre><code> HSHELL_WINDOWCREATED   =&gt; A top-level, unowned window has been created.
   HSHELL_WINDOWDESTROYED =&gt; A top-level, unowned window is about to be destroyed.
  </code></pre>
  
  <p>But:</p>
  
  <p>we'll get <code>HSHELL_WINDOWDESTROYED</code>/<code>HSHELL_WINDOWCREATED</code> also when only do Hide/Show (or set/cancel <code>WS_EX_TOOLWINDOW</code>) to any top-level unowned window (with taskbar button).
  Why? Taskbar button isn't "true" window, isn't it?</p>
  
  <p>This question primarily for MS insiders here.</p>