Hi, Per the boilerplate…. "I have reviewed this document as part of the Operational directorate’s ongoing effort to review all IETF documents being processed by the IESG. These comments  were written primarily for the benefit of the operational area directors.   Document editors and WG chairs should treat these comments just like any other last call comments. ” This is a brief, straightforward document and I believe it provides adequate guidance to implementers that it will serve to enhance interoperability, as intended. Mail policy handling is of course extremely controversial but I found the shepherd’s writeup helpful in understanding the specific issues around this document and how they were resolved. It appears to allow flexibility to implementers who want to use these codes without requiring anything in particular of those who don’t. Specifically, it appears to allow more information about mail policy to anyone who wants to deploy now, while deferring extensions that might be applicable to DMARC to that WG. Whatever your feelings regarding proper mail handling policy, this looks useful in allowing operators to signal whatever it is they do in more detail. Suzanne