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Content-ID and Message-ID Uniform Resource Locators (RFC2111)

IP.com Disclosure Number: IPCOM000002664D
Original Publication Date: 1997-Mar-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 4 page(s) / 8K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

E. Levinson: AUTHOR

Abstract

The Uniform Resource Locator (URL) schemes, "cid:" and "mid:" allow references to messages and the body parts of messages. For example, within a single multipart message, one HTML body part might include embedded references to other parts of the same message.

This text was extracted from a ASCII Text document.
This is the abbreviated version, containing approximately 35% of the total text.

Network Working Group E. Levinson

Request for Comments: 2111 XIson, Inc.

Category: Standards Track March 1997

Content-ID and Message-ID Uniform Resource Locators

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.

Abstract

The Uniform Resource Locator (URL) schemes, "cid:" and "mid:" allow

references to messages and the body parts of messages. For example,

within a single multipart message, one HTML body part might include

embedded references to other parts of the same message.

1. Introduction

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 or other data included in the message. The Content-ID

Uniform Resource Locator, "cid:", serves that purpose.

Similarly Net News readers use Message-IDs to link related messages

together. The Message-ID URL provides a scheme, "mid:", to refer to

such messages as a "resource".

The "mid" (Message-ID) and "cid" (Content-ID) URL schemes provide

identifiers for messages and their body parts. The "mid" scheme uses

(a part of) the message-id of an email message to refer to a specific

message. The "cid" scheme refers to a specific body part of a

message; its use is generally limited to references to other body

parts in the same message as the referring body part. The "mid"

scheme may also refer to a specific body part within a designated

message, by including the content-ID's address.

A note on terminology. The terms "body part" and "MIME entity" are

used interchangeably. They refer to the headers and body of a MIME

message, either the message itself or one of the body parts contained

in a Multipart message.

2. The MID and CID URL Schemes

RFC1738 [URL] reserves the "mid" and "cid" schemes for Message-ID and

Content-ID respectively. This memorandum defines the syntax for

those URLs. Because they use the same syntactic elements they are

presented together.

The URLs take the form

content-id = url-addr-spec

message-id = url-addr-spec

url-addr-spec = addr-spec ; URL encoding of RFC 822 addr-spec

cid-url = "cid" ":" content-id

mid-url = "mid" ":" message-id [ "/" content-id ]

Note: in Internet mail messages, the addr-spec in a Content-ID

[MIME] or Message-ID [822] header are enclosed in angle brackets

(<>). Since addr-spec in a Message-ID or Content-ID might contain

characters not allowed within a URL; any such character (including

"/", which is reserved within the "mi...