RFC - 2557

MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)

Original:	ftp://ftp.isi.edu/in-notes/rfc2557.txt
Authors:	J. Palme [Stockholm University/KTH], A. Hopmann [Microsoft Corporation], N. Shelness [Lotus Development Corporation]
Date:	March 1999
Category:	Proposed Standard

---

Obsoletes:
RFC-2110	MIME E-mail Encapsulation of Aggregate Documents, such as HTML (MHTML) (Obsoleted by RFC-2557prop)

Referred by:	21 RFC
Refers to:	22 RFC

---

Status

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 (1999). All Rights Reserved.

Abstract

HTML [RFC 1866] defines a powerful means of specifying multimedia documents. These multimedia documents consist of a text/html root resource (object) and other subsidiary resources (image, video clip, applet, etc. objects) referenced by Uniform Resource Identifiers (URIs) within the text/html root resource. When an HTML multimedia document is retrieved by a browser, each of these component resources is individually retrieved in real time from a location, and using a protocol, specified by each URI.

In order to transfer a complete HTML multimedia document in a single e-mail message, it is necessary to: a) aggregate a text/html root resource and all of the subsidiary resources it references into a single composite message structure, and b) define a means by which URIs in the text/html root can reference subsidiary resources within that composite message structure.

This document a) defines the use of a MIME multipart/related structure to aggregate a text/html root resource and the subsidiary resources it references, and b) specifies a MIME content-header (Content-Location) that allow URIs in a multipart/related text/html root body part to reference subsidiary resources in other body parts of the same multipart/related structure.

While initially designed to support e-mail transfer of complete multi-resource HTML multimedia documents, these conventions can also be employed to resources retrieved by other transfer protocols such as HTTP and FTP to retrieve a complete multi-resource HTML multimedia document in a single transfer or for storage and archiving of complete HTML-documents.

Differences between this and a previous version of this standard, which was published as RFC 2110(-> 2557^prop), are summarized in chapter 12.

---