protected function _extractIdentifiers($xml)
	{
		$fetch_tagdata = array(
			'ListID',
			'TxnID',
			'OwnerID',
			'TxnLineID',
			'EditSequence',
			'FullName',
			'Name',
			'RefNumber',
			);

		$fetch_attributes = array(
			'requestID',
			'iteratorID',
			'iteratorRemainingCount',
			'metaData',
			'retCount',
			'statusCode',
			'statusSeverity',
			'statusMessage',
			'newMessageSetID',
			'messageSetStatusCode',
			);

		$list = array();

		foreach ($fetch_tagdata as $tag)
		{
			if (false !== ($start = strpos($xml, '<' . $tag . '>')) and
				false !== ($end = strpos($xml, '</' . $tag . '>')))
			{
				$list[$tag] = substr($xml, $start + 2 + strlen($tag), $end - $start - 2 - strlen($tag));
			}
		}

		foreach ($fetch_attributes as $attribute)
		{
			if (false !== ($start = strpos($xml, ' ' . $attribute . '="')) and
				false !== ($end = strpos($xml, '"', $start + strlen($attribute) + 3)))
			{
				$list[$attribute] = substr($xml, $start + strlen($attribute) + 3, $end - $start - strlen($attribute) - 3);
			}
		}

		return $list;
	}