As per Relevance of the word reference, we have this rfc below:
Network Working Group E.
Request for Comments: 1873 Accurate Information Systems, Inc
Category: Experimental J.
December 1995
Message/External-Body Content-ID Access
Status of this
This memo defines an Experimental Protocol for the
community. This memo does not specify an Internet standard of
kind. Discussion and suggestions for improvement are requested
Distribution of this memo is unlimited
When using MIME [MIME] to encapsulate a structured object
consist of many elements, for example an SGML [SGML] document,
single element may occur several times. An encapsulation
maps each of the structured objects elements to a MIME entity. It
useful to include elements that occur multiple time exactly once.
accomplish that and to preserve the object structure it is
to unambiguously refer to another body part of the same message
The existing MIME Content-Type Message/External-Body access-
allow a MIME entity (body-part) to refer to an object that is not
the message by specifying how to access that object. The Content-
access method described in this document provides the capability
refer to an object within the message
1.
Consider a MIME multipart entity several of whose body parts
the same data (body) but different parameters or Content-* headers
Representing those body parts without duplicating the data in
one promotes efficient use of resources (bandwidth and
space). To achieve these benefits an access-type is defined
permits one message part to refer to another one in the same message
Levinson & Clark Experimental [Page 1]
RFC 1873 Access Type Content-ID December 1995
2. The Content-ID Access
2.1 Registration
MIME access-type name: content-
Required parameters:
Optional parameters:
Published specification: this
Person & email
to contact for
information: Ed Levinson
Additional requirements
The content-id header of the access-type=content-id
entity must match (be identical to) exactly one content-
in the same message, excluding other access-type=content-
entities. Thus, the content-id access type can only
within a multipart message and can refer to another
part anywhere in the same message
A MIME User Agent (MUA) constructs the resultant MIME
part as described below. We call the access-type=content-
MIME entity the referring body part and the MIME body
to which it refers, the one with the matching content-id
the referenced body part. The MIME entity that results
content-id access type consists of
(a) the referenced body part's content-type header
(b) the referring body part's headers except its content-
header
(c) any headers in the referenced body part not in the
one
(d) the line separating the headers from the body,
(e) the referenced body part's body
Levinson & Clark Experimental [Page 2]
RFC 1873 Access Type Content-ID December 1995
2.2 Example
The following example shows a message that consists of two
images
MIME-Version: 1.0
Content-Type: Multipart/Mixed
boundary=tiger-
--tiger-
Content-Type: image/
Content-ID: <950323.1552@XIson.com
AAAcdb...
--tiger-
Content-type: Message/External-Body
access-type=content-
Content-ID: <950323.1552@XIson.com
Content-Description
This body part is duplicated by
--tiger-lily--
The equivalent MIME entity for the second body part is
--tiger-
Content-Type: image/
Content-ID: <950323.1552@XIson.com
Content-Description
This body part is duplicated by
AAAcdb...
--tiger-
3. Security
The content-id access-type does not impact the security of
or systems. The referenced MIME entity may have
implications
Levinson & Clark Experimental [Page 3]
RFC 1873 Access Type Content-ID December 1995
4.
[822] Crocker, D., "Standard for the Format of ARPA
Text Messages", STD 11, RFC 822, UDEL, August 1982.
[SGML] ISO 8879:1988, Information processing -- Text and
systems -- Standard Generalized Markup Language (SGML).
[MIME] Borenstein, N., and N. Freed, "MIME (
Internet Mail Extensions) Part One: Mechanisms
Specifying and Describing the Format of
Message Bodies", RFC 1521, Bellcore, Innosoft
September 1993.
5. Authors'
Edward
Accurate Information Systems, Inc
2 Industrial
Eatontown, NJ 07724-2265
Phone: +1 908 389 5550
EMail:
James
90 Clarendon
London W11 2
EMail:
Levinson & Clark Experimental [Page 4]
if you see any problems within the linking, don't worry be happy,
this is version 0.1 of the Relevance System and you gotta expect some crappy subroutines sometimes,
just be content we did not write this in Java, which would have made this "bigger and better" HAHAHHA.
RFC documents can be found at I.E.T.F.
Relevance System Copyright © 2002 Spectrum WorldResearch
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