title: Php header security concert when using it?
body: <pre><code> header(string,replace,http_response_code);
  
    * string  Required. Specifies the header string to send
    * replace Optional. Indicates whether the header should replace previous or add a second header. Default is TRUE (will replace). FALSE (allows multiple headers of the same type)
    * http_response_code      Optional. Forces the HTTP response code to the specified value (available in PHP 4.3 and higher)
  </code></pre>
  
  <p>what should I concern about securiy when using this functon?</p>