I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG.  These comments were written primarily for the benefit of the security area directors.  Document
 editors and WG chairs should treat these comments just like any other last call comments.




 




This Informational document describes “considerations” for the design and operations of mailing list expanders not collocated with the sender when non-ASCII email addresses are involved. It is truly informational in that it does not prescribe
 how to deal with the various problems that one might encounter. It simply enumerates the problems, describes the alternatives, and the range of behaviors observed in existing implementations. It suggests a number of areas where future standardization would
 be helpful.




 




The document lists no security considerations. An issue discussed in the document that could be considered a security issue is that mail recipients that cannot accept non-ASCII email addresses might or might not receive messages sent to
 the list (depending on approaches the forwarder takes), and generally the original sender is not notified. I don’t recommend any changes.




 




                --Charlie