Open eBook Publication Structure Specification FAQ
Date of Last Update: 28 August 2002
Q: What is the Open eBook Publication Structure?
A: The Open eBook Publication Structure (OEBPS) is an XML-based
specification for the content, structure, and presentation of
electronic books. OEBPS is maintained by the
Open eBook Forum, a group of
over 85 organizations involved in electronic publishing. The current
version is OEBPS
1.2.
Q: Who is the intended audience for the Publication Structure?
A: Authors, editors, publishers, and content owners who want to have
their titles in a format that can be used by a variety of electronic
publishing systems and reading devices.
Q: If I produce documents that conform to the Publication Structure,
does that mean they can be rendered on all OEBPS-conformant devices?
A: Yes, OEBPS enables you to create a single electronic representation
of a publication that can be rendered by many devices. (Some devices
may require intermediate processing to transform the OEBPS Publication
into the internal format used by that device.)
Q: What is an electronic book (eBook)?
A: Because different people use this term differently, the OEBPS
Specification avoids the formal use of the term eBook within
the Specification itself and instead defines its own more precise
terminology:
-
OEBPS Publication: The digital content you read (a
“paperless” version of a book, article or other document)
-
Reading Device: The physical appliance used to render an OEBPS
Publication—examples of reading devices include dedicated
“ebook” readers, personal computers (either desktop or
portable), and palm-sized “personal digital assistants”
(PDAs)
-
Reading System: The combination of software and hardware that
processes OEBPS content and presents it to a user (the OEBPS
Specification does not require the reading system be completely
contained in the reading device; a reading system may involve
processing of content on other computers)
Q: How does OEBPS address Digital Rights Management (DRM) and copy
protection?
A: OEBPS itself does not directly address DRM and copy protection.
However, the Open eBook Forum (OeBF), the organization responsible for
maintaining OEBPS, recognizes that these are extremely important
issues for the publishing community and is leading work in this area.
In the winter of 2001, EBX, an industry consortium for protecting
copyright in electronic books, merged with OeBF. Today the OeBF Rights
and Rules Working Group is the center of DRM activity in the OeBF. The
Publication Structure Working Group and the Rights and Rules Working
Group are closely coordinating their activities to provide the
electronic publishing community with a consistent and mutually
supporting set of specifications.
Q. How is current Version 1.2 of the Publication Structure different
from the previous Version 1.0.1?
A: Quoting Section 1.4.4 (“Compatibility of Version 1.2”)
from the OEBPS 1.2 Specification:
“Version 1.2 of [OEBPS] is not meant to be a substantially
“new” Specification. However, Version 1.2 does add
functional enhancements over 1.0.1, largely supporting the goal of
allowing enhanced control over content presentational fidelity.
Specifically, the following are the most substantive additions:
-
The Basic OEBPS Document element set has been expanded.
-
All previously deprecated elements have been removed; it is now a true
subset of XHTML 1.1.
-
The OEBPS CSS subset has been augmented with numerous CSS2 properties
and values.
-
Most previously deprecated attributes have been removed.
-
The OEBPS CSS subset has been augmented with a more extensive set of
selectors.
It was a goal of Version 1.2 that all documents conformant according to
Version 1.0.1 would remain conformant under 1.2. However, removal of
elements deprecated in 1.0.1 (e.g. <font>) and the addition of
namespace requirements (see Section 1.3.3) rendered full compatibility
with Version 1.0.1 impossible.”
Q: What is the Open eBook Forum?
A: The Open eBook Forum (OeBF) is an association of hardware and
software companies, publishers, authors, users, and related
organizations, whose goal is to establish common specifications for
electronic book systems that will benefit creators of content, makers
of reading systems and, most importantly, consumers, helping to
catalyze the adoption of electronic books and increase awareness and
acceptance of the emerging electronic publishing industry. Over 85
companies and other organizations are currently members of the Open
eBook Forum.
Q: Who made the Publication Structure and how did the process work?
A: Version 1.0 of the Publication Structure was created in the winter,
spring, and summer of 1999 by the Open eBook Authoring Group.
The Authoring Group consisted of over 25 individuals from organizations
participating in the Open eBook initiative, which had been launched in
October 1998 and was convened and facilitated by NIST (the National
Institute of Standards and Technology.) The Authoring Group, like the
Open eBook initiative, included participants representing all aspects
of the electronic publishing industry, and was open to any interested
individual or organization. The Authoring Group met regularly, from
January through August 1999, to draft the Publication Structure. In
August 1999 Version 1.0 was approved by a vote of members of the Open
eBook initiative and the Specification was released 21 September 1999.
Following the release of OEBPS 1.0, the Open eBook Forum (OeBF) was
formally incorporated in January 2000.
Work then started on Version 1.0.1 (a maintenance release) by the
Publication Structure Working Group (PSWG), chartered by OeBF
as the successor to the original Authoring Group. In October 2000, PSWG
publicly solicited comments on Version 1.0 from all stakeholders, and
from the replies analyzed the various issues raised. Those issues not
requiring any significant, fundamental or substantive change to the
Specification were implemented in a new draft Version 1.0.1, reserving
the more substantive changes for consideration in a new version to be
developed subsequent to the maintenance release. Version 1.0.1 then
went through the Open eBook Forum’s review and voting procedures
and was released 02 July 2001.
In May 2000, PSWG began identifying and prioritizing requirements for a
new version of OEBPS and since then has been working to develop
additional features and functionality to be included in this new
version. In January 2002 it was decided that work completed in the
highest priority requirements area, providing content provider control
over presentation, was ready to be released. OEBPS Version 1.2,
incorporating this new presentation support along with other
corrections and improvements, went through OeBF’s review and
voting procedures, and was released as a Recommended Specification
27 August 2002.
(Another historical perspective on OEBPS development is found
here.)
The participants in the development of OEBPS (Versions 1.0, 1.0.1 and
1.2) and their affiliations are listed in the current
OEBPS 1.2
Specification, Appendix E.
Q: What was the role of NIST and the Federal government in the OeBF?
Are they imposing government-mandated standards?
A: The National Institute of Standards and Technology (NIST) is a
non-regulatory agency of the Department of Commerce. NIST’s
mission is to work with U.S. industry to stimulate economic growth
through the application of standards, measurements, and technology.
NIST facilitated the development of the Open eBook Forum and OEBPS by
acting as a neutral party convening and chairing meetings of both the
Open eBook initiative and the Authoring Group during their first year
of work, and by providing technical assistance through its Measurement
and Standards Laboratories. NIST continues its support as a neutral
member of the Open eBook Forum. The Federal government has not imposed
any standards through NIST for electronic books or for the electronic
book industry.
Q: How can I get a copy of the current Specification? Where can I learn
more?
A: The current 1.2 Specification is available from the
OEBPS
1.2 site.
Q: Is there any cost, expense or fee associated with obtaining a copy
of the Publication Structure or my use of it?
A: No.
Q: Is any part of the Publication Structure proprietary?
A: No. The Specification is based on open and public-domain
specifications, such as XML, XHTML, CSS, and Unicode — all core
languages used on the Internet and the World Wide Web.
Q: Will there be a Version 2.0 of the Specification? When? How is it
being produced? How will it be different from Version 1.2?
A: The Publication Structure Working Group is now actively at work on
Version 2.0. Goals for this version include major enhancements in the
areas of navigation and linking, internationalization, and metadata.
Although some of this work has already been completed, Version 2.0
remains in development and has no currently announced target for
completion. Backwards compatibility with the current Version 1.2 is of
course an important consideration in the design of 2.0.
Q: How can I be involved with the Publication Structure Working Group?
A: Consider joining
the Open eBook Forum. Also, industry stakeholders may submit
requirements
for consideration in future versions of OEBPS and other OeBF
specifications. It is not necessary to be a member of OeBF to submit
requirements. If you wish to participate directly in the Publication
Structure Working Group as an “invited expert” please
contact the Chair, Allen Renear.
Q: Can I use rich media such as audio or video data in an OEBPS
Publication?
A: Yes. The Specification requires all conforming reading systems to
support XML, CSS, JPEG and PNG files, but it also allows an OEBPS
Publication to contain other kinds of files as well (including audio
and video files). A conforming reading system may render these other
formats, although it is not required to do so. For any file that is not
in XML, CSS, JPEG, or PNG formats, an OEBPS Publication must also
provide a “fallback” version of the content in one of those
four formats. For instance, content in a proprietary video format must
have a fallback to content in a format that OEBPS requires reading
systems to render, such as JPEG. This is an important feature of the
OEBPS: it ensures that all OEBPS Publications can be displayed
on all reading systems while also allowing OEBPS Publications
to contain formats read by only some reading systems—a strategy
that provides support for both interoperability and advanced
functionality. This fallback mechanism also makes it possible for
accessible versions of contained formats to be included in a
publication for persons with print or hearing disabilities.
Q: Will other electronic file formats be incorporated into OEBPS?
A: OEBPS is a nonproprietary, open format. It is not owned by any
single organization. OeBF does not intend to directly incorporate any
proprietary formats into the Publication Structure, although the
fallback mechanism described above allows such formats to be included
in an OEBPS Publication, and to be rendered by conformant reading
systems—as long as the content is also available in the specific
non-proprietary formats described in the Publication Structure. In
addition, tools for converting from various proprietary formats into
OEBPS are available.
Q: What is the relationship between PDF and OEBPS?
A: Because OEBPS and PDF address different aspects of the publishing
process they are not direct competitors but can be used together in a
variety of ways. For instance, a reading system might use PDF
internally as a rendering format for OEBPS Publications. In addition,
existing PDF content, like content in any other non-OEBPS format, can
be embedded in an OEBPS Publication, provided that the Publication
contains an alternative representation of the content which can be used
by reading systems lacking PDF support.
Q: What is the relationship of OEBPS to other standards?
A: No pre-existing standard or specification provides all the features
needed to support the structuring and rendering of content in
electronic publishing. The goal of OEBPS is to provide this
comprehensive support not by developing yet another standard, but by
specifying subsets of well-established standards, most importantly:
XML, XHTML, CSS, MIME, Dublin Core, MARC, and Unicode. In addition,
OEBPS adds some specific constraints necessary for interoperability,
and defines several new mechanisms (such as the “OEBPS
Package”, and “fallbacks”) which were needed by
publishers, but which did not have equivalents in existing standards.
Q: What is the relationship of the current OEBPS 1.2 Specification to
XML? XHTML?
A: OEBPS 1.2 (as was OEBPS 1.0.1) is an XML-based specification and
allows the use of specialized XML encoding vocabularies. In addition,
to ensure a common core of familiar resources for structuring and
formatting documents, OEBPS 1.2 also identifies a set of XHTML elements
(specifically, a subset of XHTML 1.1) that may be used with their
familiar formatting semantics. Specialized XML tag-set support enables
consistency and continuity with existing in-house or standardized
domain-specific XML vocabularies. Identifying a common core of XHTML
elements ensures that existing HTML based tools, content, and expertise
can be easily exploited to produce XHTML-based OEBPS Publications.
Q: What products and services support OEBPS?
A: There are a number of reading systems and tools that support the
OEBPS Publication Structure. Many of them produced by OeBF members.
(Note that the Open eBook Forum itself makes no representation about
the OEBPS-conformance of individual systems or authoring tools.)
Q: How is accessibility being addressed by OEBPS?
A: The Publication Structure incorporates features ensuring content
can be made accessible to persons with disabilities. Specifically, the
Publication Structure incorporates accessibility features similar to
those defined in W3C’s HTML 4.0 (and XHTML 1.1) and
recommendations from the W3C’s Web Accessibility Initiative Web
Content Authoring Guidelines Recommendation. The OEBPS Working Group is
also collaborating closely with members of the accessibility community
and with the OeBF’s Accessibility Special Interest Group (SIG).
Q: How does OEBPS relate to the Digital Talking Book standards being
developed by the National Information Standards Organization (NISO) and
the Daisy Consortium?
A: The OEBPS Working Group intends to collaborate with, not compete
with, existing national and international efforts for the creation of
open standards for accessible, multimedia books. The OEBPS Working
Group includes members of the Daisy/NISO Digital Talking Book Standard
Collaboration—that effort has in fact already incorporated the
OEBPS Package structure as part of its specification, and, conversely,
the navigation model developed in the Digital Talking Book efforts is
also serving as a model for the navigation enhancements in OEBPS
Version 2.0 now under development. Continuing collaboration and
convergence with these existing standards will ensure that electronic
books will be accessible in both text and audio formats to the broadest
possible range of users.
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