$re = '/<pop title="([a-zA-Z0-9]+)">dolor<\/pop>/m';
$str = '<p><pop title="test">Lorem</pop> ipsum <pop title="dekisha">dolor</pop> sit amet, adipiscing <pop title="test">dolor</pop> elit. Cras at aliquam enim. Curabitur nisi nunc, tincidunt et efficitur ut, finibus eu arcu. Maecenas aliquam nisl sed erat ultrices venenatis. Orci varius natoque <pop title="test">dolor</pop> penatibus <pop title="test">dolor</pop> et magnis dis parturient montes, nascetur ridiculus mus. In sed semper nisi. Ut quis sapien pharetra, volutpat arcu id, mollis lacus. Duis lacus dui, laoreet ac rutrum non, aliquam sit amet mi. Donec a quam ut tortor ornare mattis et a dui. Mauris non mauris est. Etiam arcu ante, condimentum mattis cursus ac, vestibulum quis nulla. Etiam vehicula, arcu ac pretium feugiat, tellus eros pellentesque quam, at pulvinar ligula turpis eget lectus. Phasellus vitae turpis augue.</p>';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php