Media Type Registrations for the Open eBook Publication Structure (OEBPS) Package File (OPF)
Official media type for Open eBook Publication Structure package files
Conboy, G., Rivlin, J., and J. Ferraiolo, "Media Type Registrations for the Open eBook Publication Structure (OEBPS) Package File (OPF)", RFC 4839, DOI 10.17487/RFC4839, April 2007, <https://www.rfc-editor.org/info/rfc4839>.
@misc{rfc4839,
series = {Request for Comments},
number = 4839,
howpublished = {RFC 4839},
publisher = {RFC Editor},
doi = {10.17487/RFC4839},
url = {https://www.rfc-editor.org/info/rfc4839},
author = {G. Conboy and J. Rivlin and J. Ferraiolo},
title = {{Media Type Registrations for the Open eBook Publication Structure (OEBPS) Package File (OPF)}},
pagetotal = 5,
year = 2007,
month = apr,
} RFC text
Contents
Network Working Group G. Conboy
Request for Comments: 4839 J. Rivlin
Category: Informational eBook Technologies, Inc.
J. Ferraiolo
IBM
April 2007
Media Type Registrations for
the Open eBook Publication Structure (OEBPS) Package File (OPF)
Status of This Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
This document serves to register a media type for the Open eBook
Publication Structure (OEBPS) Package Files.
1. Introduction
The present document registers a media type for the Open eBook
Publication Structure (OEBPS) Package File (OPF). The OPF file is an
XML file that describes an OEBPS Publication [OEBPS]. It identifies
all other files in the publication and provides descriptive
information about them. OPF and its related standards are maintained
and defined by the International Digital Publishing Forum (IDPF).
The media type defined here is needed to correctly identify OPF files
when they are edited on disk, referenced in OEBPS Container files, or
used in other places where media types are used.
2. Security Considerations
The OPF files contain well-formed XML conforming to the XML 1.0
specification.
Clearly, it is possible to author malicious files which, for example,
contain malformed data. Most XML parsers protect themselves from
such attacks by rigorously enforcing conformance.
All processors that read OPF files should rigorously check the size
and validity of data retrieved.
There is no current provision in the OEBPS Package File standard for
encryption, signing, or authentication within the file format.
3. IANA Considerations
IANA has registered the media type application/oebps-package+xml as
specified in Section 3.1. The registration uses the template present
in [RFC4288].
3.1. Media Type for Downloadable Sounds
Type name: application
Subtype name: oebps-package+xml
Required parameters: none
Optional parameters: none
Encoding considerations: OPF files are UTF-8 or UTF-16
encoded XML
Security considerations: none
Interoperability considerations: none
Published specification: Specification is published by the
International Digital Publishing
Forum and can be found at
http://www.idpf.org/oebps/
oebps1.2/download/oeb12-xhtml.htm
Applications which use this media type:
1) eBook Technologies, Inc.
eBook reading system.
2) Microsoft Reader
3) OSoft reader
4) Content Reserve Publishing
System
5) IDPF Container WG
6) PC Reader.com
7) MobiPocket reader
Additional information:
Magic number(s): none
File extension(s): .opf
Macintosh file type code(s): TEXT
Person & email address to contact for further information:
Nick Bogaty (nbogaty@idpf.org)
Intended usage: COMMON
Restrictions on usage: None
Author: International Digital Publishing
Forum (www.idpf.org)
Change controller: International Digital Publishing
Forum (www.idpf.org)
4. Normative References
[OEBPS] "Open eBook Publication Structure 1.2", International
Digital Publishing Forum (IDPF), New York, NY USA, 2002.
[RFC4288] Freed, N. and J. Klensin, "Media Type Specifications and
Registration Procedures", BCP 13, RFC 4288, December 2005.
Authors' Addresses
Garth Conboy
eBook Technologies, Inc.
7745 Herschel Avenue
La Jolla, CA 92037
Phone: (858) 551-4950
EMail: gc@ebooktechnologies.com
John Rivlin
eBook Technologies, Inc.
7745 Herschel Avenue
La Jolla, CA 92037
Phone: (650) 255-3389
EMail: john@ebooktechnologies.com
Jon Ferraiolo
IBM
Menlo Park, CA
Phone: (650) 926-5865
EMail: jferrai@us.ibm.com
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AI ELI5
On this page
§1The eBook Package Format
The Open eBook Publication Structure (OEBPS) is a standard for packaging electronic books. Each eBook contains multiple files: the actual book content, stylesheets, images, and a manifest. The OPF file (Open Package Format) is the central XML file that describes the entire publication. It lists all the files that make up the eBook and provides metadata about them—title, author, language, and other descriptive information.
OEBPS is maintained by the International Digital Publishing Forum (IDPF). When OPF files are edited on disk, referenced in container files, or transmitted over networks, systems need a standardized way to identify what type of file they are.
An eBook is actually a folder full of files. One special file (called OPF) is like a table of contents that says what all the other files are. Computers need to recognize this special file.
§2The Media Type Registration
RFC 4839 registers the media type application/oebps-package+xml for OPF files. The application type indicates it is application-specific data, the oebps-package subtype identifies it as an OEBPS package, and the +xml suffix indicates it is XML. The files are encoded in UTF-8 or UTF-16 XML.
The registration includes the file extension (.opf) and notes the applications that use this media type, including eBook readers from various vendors such as Microsoft Reader, OSoft reader, MobiPocket, and others. The media type is marked as COMMON usage, meaning it is widely used on the Internet.
The official label for OPF files is 'application/oebps-package+xml'. When a computer sees a .opf file, it knows to treat it as an eBook package description.
§3Parsing and Security
OPF files are well-formed XML documents, so they are subject to all the security considerations of XML. The RFC notes that it is possible to create malicious files containing malformed data, but most XML parsers protect themselves by strictly enforcing XML conformance. Applications processing OPF files should rigorously validate the size and validity of retrieved data.
The OEBPS standard provides no built-in encryption, signing, or authentication mechanisms within the file format itself, so those security features would need to be handled by the application or storage system containing the OPF file.
Since OPF files are just XML, they can potentially contain harmful code. Programs reading them should be careful to check what is actually in the file.