$re = '/^(?P<mounting_type>Z)(?P<number_of_function>2)(?P<unit_type>S)(?P<unit_size>22)(?P<function_in_port>A|B|-)(?P<cracking_pressure>1|2|3|4)(?P<sep_1>-)(?P<unit_series>5X)(?P<sep_2>/|=)(?P<surface_coating>|)(?P<seal_material>V|)(?P<special_version>SO40|SO60|)(?P<additional_details>(.|[0-9])*)$/m';
$str = 'Z2S22-1-5X=
Z2S22A1-5X/V
Z2S22-1-5X/
Z2S22-2-5X/
Z2S22A1-5X/
Z2S22B1-5X/
Z2S22-4-5X/
Z2S22-1-5X/V
Z2S22B2-5X/
Z2S22-3-5X/
Z2S22A2-5X/
Z2S22-3-5X/V
Z2S22A3-5X/
Z2S22B4-5X/
Z2S22A2-5X/SO40
Z2S22A4-5X/
Z2S22-2-5X/V
Z2S22B3-5X/
Z2S22B1-5X/V
Z2S22B1-5X/SO40
Z2S22A1-5X/SO60
Z2S22B1-5X/SO60
Z2S22A1-5X/SO40
Z2S22A2-5X/V
Z2S22B2-5X/V
Z2S22A4-5X/SO40
Z2S22A3-5X/V
Z2S22B1-5X/VSO60
Z2S22B1-5X/VSO40
Z2S22-4-5X/V
Z2S22B3-5X/SO40
Z2S22A1-5X=SO60
Z2S22B3-5X/V
';
preg_match_all($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