> As to the ERROR-IS codes, they don't have to be complicated. When an > error condition is detected, they would be an OPTIONAL way to further > describe the error. The only requirement would be that no fales > descriptions be sent. The coding can be structured with varying amounts > of information. Whatever follows the number can be text taken as a > comment. What will programs do with this information about the cause of the error? It seems to me that the only reason for putting such information into a header is that a program might process it in some way. A person can see what the error was by reading the text of the rejection notice.