I'm still not sure why it is not either definition and why this is not allowed? Section 1.1.1 says An implementation which does not include a particular option MUST be prepared to interoperate with another implementation which does include the option, though perhaps with reduced functionality. Our spec simply defines *reduced functionality* as an Error of NotSupported. I'm not sure why this change is needed? We need to limit out discussions to essential changes. Regards, David