$re = '/((?:[A-Z0-9]{1,4}|[Bb]lank)(?=\h[-–]\h)|[Bb]lank)(?:\h[-–]\h|\|)?(.*?)(?=[Bb]lank|\||[A-Z0-9]{1,4}\h[-–]\h|$)/m';
$str = '01 - First Value|02 - Second Value|Blank - Ignore
A - First ValueblankB - Second ValueC - Third Value';
preg_match_all($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