This is an OPS-DIR review of Extended DNS Errors <draft-ietf-dnsop-extended-error>

This ID defines a use of the EDNS0 extension mechanism that can be used by a DNS resolver to provide additional detail about DNS lookup issues as well as defining an initial set of 24 codes that can be used to provide specific failure reasons. 

The document is clearly written. (But I expect that not all of the acknowledgements should be retained in the RFC)

From an operations point of view, the additional information provided by these error codes will be quite helpful in diagnosing DNS errors. But, as with most error information, it will be difficult to present the error information in a way that will make sense to the average Internet user, thus this information may be mostly useful to IT support staff.