(PHP 4 >= 4.0.1, PECL yaz >= 0.9.0)
yaz_addinfo — Returns additional error information
$id): stringReturns additional error information for the last request on the server.
With some servers, this function may return the same string as yaz_error().
A string containing additional error information or an empty string if the last operation was successful or if no additional information was provided by the server.