title: iconv UTF-8//IGNORE still produces "illegal character" error
body: <pre><code>$string = iconv("UTF-8", "UTF-8//IGNORE", $string);
  </code></pre>
  
  <p>I thought this code would remove invalid UTF-8 characters, but it produces <code>[E_NOTICE] "iconv(): Detected an illegal character in input string"</code>. What am I missing, how do I properly strip a string from illegal characters?</p>