One document matched: draft-levinson-cid-01.txt

Differences from draft-levinson-cid-00.txt

       MIMESGML Working Group                           E. Levinson
       Internet Draft: CID and MID URLs    Accurate Info. Sys., Inc.
       <draft-levinson-cid-01.txt>                 October 12, 1995

           Content-ID and Message-ID Uniform Resource Locators

       This draft document is being circulated for comment.  Please
       send your comments to the authors or to the ietf-822 mail
       list <ietf-822@list.cren.net>.  If consensus is reached,
       this Access Type may be registered with IANA and this
       document may be submitted to the RFC editor as an
       Informational protocol specification.

       Status of this Memo

       This document is an Internet Draft; Internet Drafts are
       working documents of the Internet Engineering Task Force
       (IETF) its Areas, and Working Groups.  Note that other
       groups may also distribute working documents as Internet
       Drafts.

       Internet Drafts are draft documents valid for a maximum of
       six months.  They may be updated, replaced, or obsoleted by
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       Internet Drafts as reference material or to cite them other
       than as a "working draft" or  "work in progress".

       Please check the abstract listing in each Internet Draft
       directory for the current status of this or any other
       Internet Draft.

       Abstract

       The Uniform Resource Locator (URL) scheme, "cid", allows
       compound or aggregate objects in a multipart mail message to
       refer to one another by their body part labels.

       1. Introduction

       There is a desire to refer to email or netnews messages and
       the body parts of such messages using Uniform Resource
       Locators (URLs).  The MID and CID schemes described below
       permit such references.

       The use of [MIME] within email to convey Web pages and their
       associated images requires a URL scheme to permit the HTML
       to refer to the images included in the message.  A Content-
       ID Uniform Resource Locator serves that purpose.  Similarly
       NetNews readers use Message-IDs to link related messages
       together.  The Message-ID URL provides a scheme for that
       purpose.

       2. The MID and CID URL Schemes




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       RFC1738 [URL] reserves the scheme "cid" for Content-ID.
       This memorandum defines the syntax for the cid URL.  Because
       a Message-ID scheme uses the same syntatic elements both are
       presented together.


       The URLs takes the form

               cidurl     = "cid" ":" id-spec

               midurl     = msgmid / cidmid

               msgmid     = "mid" ":" id-spec

               cidmid     = msgmid "#" cidurl

               id-spec    = local-part "@" hostname
                                           ; globally unique

               local-part = 1*uchar

       where id-spec is a restricted form of "addr-spec" as defined
       in [RFC822] and hostname and uchar are defined in [RFC1738,
       sec 3.1].  The purpose of the restriction on addr-spec is to
       eliminate special characters from the cid URL.  Such
       characters can be problematical in many environments (e.g.,
       HTML and SGML) in which the cidurl may be used.  Special
       characters are representable, however, by using the escape
       mechanism provided in [RFC1738] Cidurls and midurls are a
       subset of MIME content-IDs and RFC822 message-IDs
       respectively.

       A msgmid refers to the entire message and the cidmid refers
       to a single body part within the referenced message.

       The cidurls and midurls differ from message-ids and MIME
       content-ids in the inclusion of the scheme part and in the
       omission of the leading and trailing brackets, "<" and ">",
       and the restricted character set.  To transform a cidurl or
       midurl into a valid content-id or message-id, surround the
       id-spec part with the enclosing brackets, i.e.,

               content-id = "<" id-spec ">".

               message-id = "<" id-spec ">".

       Cidurls and midurls are globally unique [MIME, p.19].  A
       common technique for generating a globally unique cidurl and
       midurl uses a time and date stamp with the local host's
       domain name, e.g., 950124.162336@XIson.com.

       3. Security

       Security issues are not addressed in this memorandum.



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       4. References


       [822]   Crocker, D., Standard for the Format of ARPA Internet Text Mes-
               sages, August 1982, University of Delaware, RFC 822.

       [MIME]  Borenstein, N. and Freed, N., MIME (Multipurpose Internet Mail
               Extensions): Mechanisms for Specifying and Describing the Format
               of Internet Message Bodies, June 1992, RFC 1341.

       [SGML]  ISO 8879:1988, Information processing -- Text and office systems
               -- Standard Generalized Markup Language (SGML).

       [URL]   Berners-Lee, T., Masinter, L., and McCahill, M., Uniform
               Resource Locators (URL), December 1994, RFC 1738.

       5. Acknowledgements

       This work reflects the ideas freely provided to the author by Harald T.
       Alvestrand, UNINETT, including Tim Berners-Lee, W3O, who pointed me at
       the idea of using a URL "scheme" in the SGML encapsulation proposal,
       Daniel W. Connolly, HAL, and Roy T. Fielding, UCI.

       6. Author's Address

       Edward Levinson
       Accurate Information Systems, Inc.
       2 Industrial Way
       Eatontown, NJ  07724-2265
       USA
       +1 908 389 5550
       <ELevinson@Accurate.com>

























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