public function getTags()
   {
     if ($this->_tags !== null)
     {
       return $this->_tags;
     }
     return array(
       'b' => array(
         'hasOption' => false,
         'replace' => array('<b>', '</b>')
       ),
       'i' => array(
         'hasOption' => false,
         'replace' => array('<i>', '</i>')
       ),
       'u' => array(
         'hasOption' => false,
         'replace' => array('<span style="text-decoration: underline">', '</span>')
       ),
       's' => array(
         'hasOption' => false,
         'replace' => array('<span style="text-decoration: line-through">', '</span>')
       ),
       'color' => array(
         'hasOption' => true,
         'optionRegex' => '/^(rgb\(\s*\d+%?\s*,\s*\d+%?\s*,\s*\d+%?\s*\)|#[a-f0-9]{6}|#[a-f0-9]{3}|[a-z]+)$/i',
         'replace' => array('<span style="color: %s">', '</span>')
       ),
       'font' => array(
         'hasOption' => true,
         'optionRegex' => '/^[a-z0-9 \-]+$/i', // regex matched to HTML->BB code regex
         'replace' => array('<span style="font-family: \'%s\'">', '</span>')
       ),
       'size' => array(
         'hasOption' => true,
         'optionRegex' => '/^[0-9]+(px)?$/i',
         'callback' => array($this, 'renderTagSize'),
       ),
etc...