IANA Registration of Content-Type Header Field Parameter 'forwarded'
draft-melnikov-iana-reg-forwarded-00

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Network Working Group                                        A. Melnikov
Internet-Draft                                                 Isode Ltd
Intended status: Informational                              B. Hoeneisen
Expires: May 7, 2020                                      pEp Foundation
                                                       November 04, 2019

  IANA Registration of Content-Type Header Field Parameter 'forwarded'
                  draft-melnikov-iana-reg-forwarded-00

Abstract

   This document defines a new Content-Type header field parameter named
   "forwarded" for "message/rfc822" and "message/global" media types,
   and its registration with IANA.

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   This Internet-Draft will expire on May 7, 2020.

Copyright Notice

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.1.  Use Cases . . . . . . . . . . . . . . . . . . . . . . . .   2
     1.2.  Implementations . . . . . . . . . . . . . . . . . . . . .   3
     1.3.  Requirements Language . . . . . . . . . . . . . . . . . .   3
     1.4.  Terms . . . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  Specification . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Example . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   5
   5.  Privacy Considerations  . . . . . . . . . . . . . . . . . . .   5
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   5
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   5
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   6
   Appendix A.  Additional Example (pEp) . . . . . . . . . . . . . .   6
   Appendix B.  Document Changelog . . . . . . . . . . . . . . . . .   8
   Appendix C.  Open Issues  . . . . . . . . . . . . . . . . . . . .   8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   This document defines a new Content-Type header field parameter
   [RFC2045] for "message/rfc822" and "message/global" [RFC6532] media
   types with name "forwarded".  The parameter value is case-
   insensitive and can be either "yes" or "no".  Setting the value to
   "no" is meaningful when used within S/MIME or PGP/MIME signed or
   encrypted body parts (cf.
   [I-D.ietf-lamps-header-protection-requirements].  The value "yes"
   means that the message nested inside "message/rfc822" (or "message/
   global") is a simple forwarded message.  If the parameter is missing,
   the default assumption is the message has been forwarded.

1.1.  Use Cases

   Two use cases have been discovered so far:

   1.  This parameter indicates whether a nested message is signed and/
       or encrypted (S/MIME or PGP/MIME), which tells the receiving side
       how to display the message to the user.  Currently, many email
       clients display "weird artefacts" to users due to this missing
       information.

   2.  This parameter indicates to mailing lists which email messages
       are forwarded, and which are signed and/or encrypted (S/MIME or
       PGP/MIME), and how to handle these respective messages.

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1.2.  Implementations

   At this time, there are two known email systems which use this