Technical Summary
The Internet Message Format (RFC 5322) allows "group" syntax in some
email header fields, such as "To:" and "CC:", but not in "From:" nor
"Sender:". This document updates RFC 5322 to relax that restriction,
allowing group syntax in those latter fields, as well as in "Resent-
From:" and "Resent-Sender:", in certain situations.
This change is required to make the relationship between an
internationalized POP or IMAP server handing messages with non-ASCII
material in message headers and legacy POP or IMAP clients work in
some of the ways approved by the EAI WG. Without this change, such
messages effectively become completely undeliverable and may be lost.
Working Group Summary
The specification has been reviewed informally on the EAI and 822
mailing lists and extensively discussed among EAI participants as
part of that effort (see above). Other than as noted below, there
have been no significant objections; smaller issues that have been
identified have already been addressed in the document.
One individual has expressed concerns about the change represented by
the document. The core of that concern has been addressed by adding
an Applicability Statement to the specification and adjusting some
other text. He would like us to go further, perhaps abandoning the
change entirely. There seems to be consensus on the mailing lists
that have reviewed the document that his concerns are largely
unfounded (no one else has spoken up in favor of his point of view
and several people have made that observation) as well as primarily
focused on a protocol that has not been considered in the IETF, much
less standardized.
Given that concern, the Security Considerations provisions should be
checked during IETF Last Call, but, especially if use of the change
is confined to carefully-selected cases as the document recommends,
the document Shepherd is convinced that there are no outstanding
important issues in that or any other area.
The small amount of ABNF in the document has been checked carefully
and adjusted for maximum clarity.
Document Quality
Implementation of this change is basically trivial. Parsers for
email message headers already have to contain the necessary
provisions and code to support group syntax in other contexts, so
allowing that syntax for additional backward-pointing fields should
be just a matter of changing the applicable processing from one
already-present case to another. If any additional code or
processing is needed, it will be control the specific cases in which
the construction is allowed (as advised by the Applicability
Statement).
Personnel
The document shepherd is John C Klensin. The responsible Area
Director is Pete Resnick.