$re = '/\[[^\]]+]/m';
$str = '[01]ABC0007[0d0a]BB BABLOXC[0d0a]067989 PLPXBNS[0d0a02]BBR OIC002 L5U0/P AMD KAP 041800 T1200AND 2+00[0d0a0b03]';
$subst = " ";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
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