The Use of URLs as Meta-Syntax for Core Mail List Commands and their Transport through Message Header Fields
RFC 2369

Document Type RFC - Proposed Standard (July 1998; No errata)
Was draft-baer-listspec (individual)
Last updated 2013-03-02
Stream Legacy
Formats plain text html pdf htmlized bibtex
Stream Legacy state (None)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state RFC 2369 (Proposed Standard)
Telechat date
Responsible AD (None)
Send notices to (None)
Network Working Group                                      G. Neufeld
Request for Comments: 2369                                      Nisto
Category: Standards Track                                     J. Baer
                                                 SkyWeyr Technologies
                                                            July 1998

       The Use of URLs as Meta-Syntax for Core Mail List Commands
           and their Transport through Message Header Fields

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (1998).  All Rights Reserved.

Abstract

   The mailing list command specification header fields are a set of
   structured fields to be added to email messages sent by email
   distribution lists. Each field typically contains a URL (usually
   mailto [RFC2368]) locating the relevant information or performing the
   command directly. The three core header fields described in this
   document are List-Help, List-Subscribe, and List-Unsubscribe.

   There are three other header fields described here which, although
   not as widely applicable, will have utility for a sufficient number
   of mailing lists to justify their formalization here. These are
   List-Post, List-Owner and List-Archive.

   By including these header fields, list servers can make it possible
   for mail clients to provide automated tools for users to perform list
   functions. This could take the form of a menu item, push button, or
   other user interface element. The intent is to simplify the user
   experience, providing a common interface to the often cryptic and
   varied mailing list manager commands.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in RFC 2119.

Neufeld & Baer              Standards Track                     [Page 1]
RFC 2369                  URLs as Meta-Syntax                  July 1998

1. Introduction

   This is a proposal for additional header fields to be added to email
   messages sent by email distribution lists. The content of each new
   field is typically a URL - usually mailto [RFC2368] - which locates
   the relevant information or performs the command directly. MTAs
   generating the header fields SHOULD usually include a mailto based
   command, in addition to any other protocols used, in order to support
   users who do not have access to non-mail-based protocols.

   Implementing these fields will be optional. Significant functionality
   and convenience can be gained by including them, however. Many list
   managers, especially as the proposal first gains acceptance, MAY
   choose to implement only one or two of the fields.  The List-Help
   field is the most useful individual field since it provides an access
   point to detailed user support information, and accommodates almost
   all existing list managers command sets. The List-Subscribe and
   List-Unsubscribe fields are also very useful, but cannot describe
   some list manager syntaxes at this time (those which require variable
   substitution). See appendix A.5 for an explanation.

   The description of command syntax provided by the fields can be used
   by mail client applications to provide simplified and consistent user
   access to email distribution list functions. This could take the form
   of menu items, push buttons, or other user interface elements.  The
   intent is to simplify the user experience, providing a common
   interface to the often cryptic and varied mailing list manager
   commands.

   Consideration has been given to avoiding the creation of too many
   fields, while at the same time avoiding the overloading of individual
   fields and keeping the syntax clear and simple.

   The use of these fields does not remove the requirement to support
   the -Request command address for mailing lists [RFC2142].

2. The Command Syntax

   The list header fields are subject to the encoding and character
   restrictions for mail headers as described in [RFC822]. Additionally,
   the URL content is further restricted to the set of URL safe
   characters [RFC1738].

   The contents of the list header fields mostly consist of angle-
   bracket ('<', '>') enclosed URLs, with internal whitespace being
   ignored. MTAs MUST NOT insert whitespace within the brackets, but
   client applications should treat any whitespace, that might be
   inserted by poorly behaved MTAs, as characters to ignore.

Neufeld & Baer              Standards Track                     [Page 2]
RFC 2369                  URLs as Meta-Syntax                  July 1998
Show full document text