$re = '/(?is)(?<=\NAME1\b).*?(?=\bNAME2\b|\bNAME3\b|NAME4|NAME5|NAME6\b)/m';
$str = 'NAME1 THIS IS ONLY A TEST DATA
THIS IS NOT THE ACTUAL DATA
NAME2
NAME1 THIS IS ONLY A TEST DATA
THIS IS NOT THE ACTUAL DATA
NAME3
NAME1 THIS IS ONLY A TEST DATA
THIS IS NOT THE ACTUAL DATA
NAME6
NAME1 THIS IS ONLY A TEST DATA
THIS IS NOT THE ACTUAL DATA
NAME5';
preg_match_all($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