$re = '/(?<city>[A-Z]{1,2})([^\S\r\n]|-)*(?<letters2>[A-Z]){1,2}[^\S\r\n]*(?<numbers>[0-9]{1,4})[^\S\r\n]*(?<suffix>E)?/m';
$str = ' AB CD 1334E
A-CD 1334E
RZ-SN440 E
RZ - F4 E
RZ - F4223';
preg_match_all($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