I've never been an expert in regular expressions.  Below, I'm pasting in several preg_replace commands that are in a PHP script.  I'm hoping that someone here that knows regular expressions like the back of their hands can tell me what these are doing faster than I could possibly decipher them on my own.

      $string = preg_replace('#(<[^>]+[\x00-\x20\"\'\/])(on|xmlns)[^>]*>#iUu', "$1>", $string);

      $string = preg_replace('#([a-z]*)[\x00-\x20\/]*=[\x00-\x20\/]*([\`\'\"]*)[\x00-\x20\/]*j[\x00-\x20]*a[\x00-\x20]*v[\x00-\x20]*a[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iUu', '$1=$2nojavascript...', $string);
echo "<br>String is now {$string}<br>";
     
      $string = preg_replace('#([a-z]*)[\x00-\x20\/]*=[\x00-\x20\/]*([\`\'\"]*)[\x00-\x20\/]*v[\x00-\x20]*b[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iUu', '$1=$2novbscript...', $string);
echo "<br>String is now {$string}<br>";
     
      $string = preg_replace('#([a-z]*)[\x00-\x20\/]*=[\x00-\x20\/]*([\`\'\"]*)[\x00-\x20\/]*-moz-binding[\x00-\x20]*:#Uu', '$1=$2nomozbinding...', $string);
      $string = preg_replace('#([a-z]*)[\x00-\x20\/]*=[\x00-\x20\/]*([\`\'\"]*)[\x00-\x20\/]*data[\x00-\x20]*:#Uu', '$1=$2nodata...', $string);

      $string = preg_replace('#(<[^>]+[\x00-\x20\"\'\/])style[^>]*>#iUu', "$1>", $string);

      $string = preg_replace('#</*\w+:\w[^>]*>#i', "", $string);

Thank you in advance for any assistance.

Gary.