$re = '/\b[A-Z]{1,2}\d{1,2}\s{0,}[A-Z]{3}\b/m';
$str = 'My 2.2L car (L4 MUP) is a Range Rover Evoque and was registered in 2012
Who is the owner of car AB12 CDE?
S44 SHD is an example of a personalised reg plate
My password is ALL4ONE or 14ALL but my car is AL4ONE
Your Name is RAJ SOOKRAH
GHESYT5 GK66 DMO 46703h ';
preg_match_all($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