$re = '/(?:\b[A-Z]*\d+\.\d{2}| )([A-Z0-9]{2}) /m';
$str = 'ABC WS PIT342.55USD342.55END
ABC WS YMQ234.03WS TOY234.03USD468.06END
FUR BB LAB Q10.00 199.00USD209.00END
YAS DG TYY Q AWSMSN11.32 2503.08LD VET Q JKLOLE11.32 2503.08USD5028.80END
PPP VP LAP Q10.00 M342.41EE SFD Q10.00 282.24USD644.65END
YAS DL X/XXX MO X/POP DF PSC241.30ET X/SAE DL X/KOO DL CSG269.80USD511.10END
pattern1: " ([A-Z0-9]{2}) "
pattern2: "\\b[A-Z ]*\\d+\\.\\d{2}([A-Z0-9]{2}) "';
preg_match_all($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