$re = '/".*"\K|[^"\n]+/';
$str = '{LID.P21_MA4_DB,new String[]{"Assumed probability of premise value(s)","This is only useful if a premise value is defined. Reduces query execution time."}},
{LID.HOST_CFG_CASE_DOCS_FOLDER_SERVER_PATH,"Case documents folder path server-side"},
{LID.P12_MA3_T0,"Main form {0} - {1}"},';
$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