public function get_copyright()
	{
		if ($return = $this->get_item_tags(SIMPLEPIE_NAMESPACE_ATOM_10, 'rights'))
		{
			return $this->sanitize($return[0]['data'], $this->registry->call('Misc', 'atom_10_construct_type', array($return[0]['attribs'])), $this->get_base($return[0]));
		}
		elseif ($return = $this->get_item_tags(SIMPLEPIE_NAMESPACE_DC_11, 'rights'))
		{
			return $this->sanitize($return[0]['data'], SIMPLEPIE_CONSTRUCT_TEXT);
		}
		elseif ($return = $this->get_item_tags(SIMPLEPIE_NAMESPACE_DC_10, 'rights'))
		{
			return $this->sanitize($return[0]['data'], SIMPLEPIE_CONSTRUCT_TEXT);
		}

		return null;
	}