Browse Prior Art Database

Internationalized Email Headers (RFC6532) Disclosure Number: IPCOM000215107D
Original Publication Date: 2012-Feb-01
Included in the Prior Art Database: 2012-Feb-18
Document File: 22 page(s) / 23K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

A. Yang: AUTHOR [+3]


Internet mail distinguishes a message from its transport and further divides a message between a header and a body [RFC5322]. Internet mail header field values contain a variety of strings that are intended to be user-visible. The range of supported characters for these strings was originally limited to [ASCII] in 7-bit form. MIME [RFC2045] [RFC2046] [RFC2047] provides the ability to use additional character sets, but this support is limited to body part data and to special encoded-word constructs that were only allowed in a limited number of places in header field values.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 12% of the total text.

Internet Engineering Task Force (IETF)                           A. Yang Request for Comments: 6532                                         TWNIC Obsoletes: 5335                                                S. Steele Updates: 2045                                                  Microsoft Category: Standards Track                                       N. Freed ISSN: 2070-1721                                                   Oracle                                                            February 2012

                     Internationalized Email Headers


   Internet mail was originally limited to 7-bit ASCII.  MIME added    support for the use of 8-bit character sets in body parts, and also    defined an encoded-word construct so other character sets could be    used in certain header field values.  However, full    internationalization of electronic mail requires additional    enhancements to allow the use of Unicode, including characters    outside the ASCII repertoire, in mail addresses as well as direct use    of Unicode in header fields like "From:", "To:", and "Subject:",    without requiring the use of complex encoded-word constructs.  This    document specifies an enhancement to the Internet Message Format and    to MIME that allows use of Unicode in mail addresses and most header    field content.

   This specification updates Section 6.4 of RFC 2045 to eliminate the    restriction prohibiting the use of non-identity content-transfer-    encodings on subtypes of "message/".

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force    (IETF).  It represents the consensus of the IETF community.  It has    received public review and has been approved for publication by the    Internet Engineering Steering Group (IESG).  Further information on    Internet Standards is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,    and how to provide feedback on it may be obtained at

 Yang, et al.                 Standards Track                    [Page 1]
 RFC 6532             Internationalized Email Headers       February 2012

 Copyright Notice

   Copyright (c) 2012 IETF Trust and the persons identified as the    document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal    Provisions Relating to IETF Documents    (