ANSI/NISO Z39.86-200x Version 1.0.0
File Specifications for the Digital Talking Book

Final Draft

September 28, 2001

Abstract: This standard defines the format and content of the electronic file set that comprises a digital talking book (DTB). It uses established and new specifications to delineate the structure of DTBs whose content can range from XML text only, to text with corresponding spoken audio, to audio with little or no text. DTBs are designed to make print material accessible and navigable for blind or otherwise print-disabled persons.

Copyright © 2001 by National Information Standards Organization


Table of Contents

  1. General Information
  2. Overview
  3. The DTB Package File
  4. Content Format for Text
  5. Audio File Formats
  6. Image File Formats
  7. Synchronization of Media Files
  8. Navigation Control File (NCX)
  9. Portable Bookmarks and Highlights
  10. Resource File
  11. Packaging Files for Distribution
  12. Presentation Styles
  13. Types of DTB
  14. Digital Rights Management
  15. Time-Scale Modification
  16. Conformance
  17. References to Other Specifications/Documents

Foreword

(This foreword is not a part of the American National Standard for Digital Talking Books... . It is included for information only.)

This standard presents the file specifications for digital talking books (DTBs) for blind, visually impaired, physically handicapped, learning-disabled, or otherwise print-disabled readers. For many years, "talking books" have been made available to print-disabled readers on analog media such as phonograph records and audiocassettes. These media serve their users well in providing human-speech recordings of a wide array of print material in increasingly robust and cost-effective formats. However, analog media are limited in several respects when compared to a print book. First, they are by their nature linear presentations, which leaves much to be desired when reading reference works, textbooks, magazines, and other materials which are often accessed randomly. Digital media offer readers the ability to move around a book or magazine as freely as (and more efficiently than) a sighted reader flips through a print book. Second, analog recordings do not allow users to interact with the book, placing bookmarks, highlighting material, and so forth. A DTB offers this capability, storing the bookmarks and highlights separate from, but associated with, the DTB itself. Third, talking book users have long complained that they do not have access to the spelling of the words they hear. As will be explained below, some DTBs will include a file containing the full text of the work, synchronized with the audio presentation, thereby allowing readers to locate specific words and hear them spelled. Finally, analog audio offers readers only one version of the document. If, for example, a book contains footnotes, they are either read where referenced, which burdens the casual reader with unwanted interruptions, or grouped at a location out of the flow of the text, making them difficult for interested readers to access. A DTB allows the user to easily skip over or read footnotes. The Digital Talking Book offers the print-disabled user a significantly enhanced reading experience -- one that is much closer to that of the sighted reader using a print book. This standard describes the various files that make up a DTB and specifies how each must be formatted.

The DTB goes far beyond the limits imposed on analog audio books because they can include not just the audio rendition of the work, but the full textual content and images as well. Because the textual content file is synchronized with the audio file, a DTB offers multiple sensory inputs to readers, a great benefit to learning-disabled readers, for example. Some visually impaired readers may choose to listen to most of the book, but find that inspecting the images provides information not available in the narrative flow. Others may opt to skip the audio presentation altogether and instead view the text file via screen-enlarging software. Braille readers may prefer to read some or all of the document via a refreshable Braille display device connected to their DTB player and accessing the textual content file.

Digital Talking Books are not tied to a single distribution medium. CD-ROMs will be used first but DTBs will be portable to any digital distribution medium capable of handling the large files associated with digital audio recordings. Regardless of how a DTB is distributed, however, it will normally be in the context of a digital rights management system.

The initiative behind this document grew from a desire to standardize DTB file structures, in the hope that it might prevent a recurrence of the multiple formats currently used for talking books throughout the world. This document benefited greatly from the work of the DAISY Consortium, whose members had broken much of the ground covered in this standard and who contributed enormously to the solution of the many problems encountered.

NISO Voting Members

To be added by NISO.

NISO Board of Directors

To be added by NISO.

Standards Committee AQ

Standards Committee AQ on Digital Talking Books had the following members at the time this standard was approved:

Contents

Acknowledgements

Standards Committee AQ gratefully acknowledges the contributions made by the DAISY Consortium (www.daisy.org) to this work. The Consortium created a series of open international specifications (DAISY 2.0 1998, DAISY 2.01 1999, and DAISY 2.02 2001) that formed the foundation on which this standard is built. DAISY representatives served on Committee AQ since its inception and knowledge gained in their work on DAISY projects greatly informed the complex discussions and decisions leading to the creation of this document. In addition, they hosted several list-servs on which many issues critical to DTB work in general, and to this standard specifically, were discussed and resolved. It is no exaggeration to state that without their groundbreaking efforts and their ongoing contributions to Committee work, this standard would not exist in anything like its current level of sophistication.

In addition, the Committee wishes to thank the following individuals for their substantial assistance to the process of creating the standard: Robert Berkovitz, Sensimetrics Corporation; Harvey Bingham; Mike Brown; John Churchill, Recording for the Blind and Dyslexic; Manon Gaudet, VisuAide, Inc.; Al Gilman; Markus Gylling, Swedish Library of Talking Books and Braille; Steve Jacobs, NCR Corporation; Lynn Leith, Canadian National Institute for the Blind; Tatsu Nishizawa, Plextor Corporation; Dave Pawson, Royal National Institute for the Blind; James Pritchett, Recording for the Blind and Dyslexic; Dr. Gregg Vanderheiden, TRACE Research and Development Center, University of Wisconsin; Mr. Paul Vassallo, National Institute of Standards & Technology; with special thanks to members of the DAISY Consortium's Specifications and Guidelines Work Team and DTD Work Team. Thanks also to these members of the W3C Synchronized Multimedia (SYMM) Working Group: Dick Bulterman, Oratrix; Wo Chang, NIST; Lloyd Rutledge, CWI; Patrick Schmitz, Microsoft.

Contents

1. General Information

1.1 Purpose and Scope of Standard

(This section is informative.)

This standard establishes file specifications for digital talking books (DTBs) for blind, visually impaired, physically handicapped, learning-disabled, or otherwise print-disabled readers. Its purpose is to ensure interoperability across service organizations and vendors providing content and playback systems to the target population.

This standard provides specifications applicable to all aspects of digital talking book production and rendering, including authoring tools for DTBs, hardware- or software-based playback devices, and compliance-testing software.

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1.2 Definitions

(This section is informative)

The following abbreviations, acronyms, phrases, and terms are used in this standard as defined below. In the following definitions and throughout the standard, bracketed items correspond to entries in section 17, "References to Other Specifications/Documents," where the full URL is provided for each reference.

Accessible
Fully usable by the target population.
CSS
Cascading Style Sheets [CSS] is a mechanism for adding style (e.g. fonts, colors, spacing, formatting) to HTML or XML documents.
DRM
Digital Rights Management is a system of tools and processes that protect intellectual property when it is encoded and distributed in digital form.
DTB
The Digital Talking Book content data set that complies with the specifications in this standard.
DTBook
An XML element set (dtbook.dtd) that defines the markup for the textual content of a DTB.
DTD
The Document Type Definition file contains machine- and human-readable rules that define allowable XML markup for a particular application.
FIXED
When used in definitions of attributes, means the attribute has a single, fixed value specified in the DTD.
Fragment Identifier
A means to address a named place in a document. For reference within the current document, the reference part is to a named target, and begins with "#". See URI for addressing into another document.
Global navigation
Movement to user-selected portions of a document, with that movement enabled by the NCX. Navigation targets may be headings representing the hierarchical structure of the document or specific points such as pages, notes, sidebars, etc.
IMPLIED
When used in definitions of attributes, means the attribute is optional, as opposed to REQUIRED.
Informative
An explanatory part of this standard. Contrast with Normative.
Local navigation
Movement within a document at a granularity finer than that provided by the NCX. For example, navigation by paragraph or sentence, or within a table or nested list. Precise local navigation can be controlled by the textual content file or the SMIL file(s); the granularity is limited by the degree to which the textual content file has been marked up or the level to which synchronization has been applied in the SMIL file(s). Time-based movement through a document (similar to fast-forward and rewind on an analog cassette) may also be implemented.
Manifest
A component of the Package File, the Manifest lists all files included in the DTB.
May
In this standard, the word may means that a course of action is optional.
Media Unit
A single object on which a DTB is stored for distribution to the reader. For example, a single CD-ROM disk.
Must
In this standard, the word must is to be interpreted as a mandatory requirement on the content or implementation. The term shall has the same definition as must.
NCX
The Navigation Control file for XML applications (NCX) provides the reader efficient and flexible access to the hierarchical structure of a DTB as well as direct access to selected elements such as page numbers, notes, figures, etc.
Normative
A portion of the standard that supplies precise specifications rather than background or explanation. Contrast with Informative. Notes within a normative section may be informative.
OEBF
The Open eBook Forum [OEBF] is an organization formed to create and maintain standards and promote the successful adoption of electronic books. The Open eBook Publication Structure Version 1.0.1 provides a specification for representing the content of a book when it is converted from print to electronic form. This DTB standard utilizes a subset (the Package File) of that specification.
OPF
Open eBook Forum Package File. See Package File.
Package File
The Open eBook Forum Package File (OPF) is an XML file conforming to the oebpkg101.dtd that contains administrative information about the DTB, the files that comprise it, and how these files interrelate.
Playback
With regard to implementations, playback refers to the methods used to render the DTB content. Playback may include audio, Braille, large print, and synthetic speech as appropriate for the content and as supported by the playback system.
Playback System
The hardware/software platform which renders the contents of a DTB to a user. Synonymous with Player.
Player
See Playback System.
Reader
The person reading the digital talking book. Synonymous with User.
REQUIRED
When used in definitions of attributes, means the attribute is required, as opposed to IMPLIED.
Shall
See Must
Should
In this standard, the word should means that a course of action is recommended but not required.
SMIL
The Synchronized Multimedia Integration Language [SMIL] is a W3C recommendation (SMIL 2.0) utilized in this standard to control the synchronized presentation of content in multiple media.
Spine
A component of the Package File, the Spine lists in default reading order the SMIL files included in the DTB.
Target population
The target population consists of blind, visually impaired, physically handicapped, learning-disabled, and otherwise print-disabled readers.
Textual Content File
The content of the subject document in a character set specified by ISO/IEC 10646 [ISO 10646] to which XML markup valid to the DTBook DTD has been applied.
TSM
Time-scale modification. Varying playback rate (both slower and faster than real time) while maintaining constant pitch.
URI
A Uniform Resource Identifier is a compact string of characters for identifying resources: documents, images, audio files, etc. Within a DTB, they are most likely to appear as attribute values for various XML elements, used as a way of identifying other documents or files either in whole or part. For the purposes of this specification, URIs must adhere to the syntax defined in RFC 2396 [RFC 2396]. A URI may include a fragment identifier suffix beginning with "#" that matches some named anchor in the target document. See Fragment Identifier.
User
See Reader.
XML
The Extensible Markup Language [XML] is a standardized language for marking up files containing structured information.
XSL
Extensible Stylesheet Language: A series of recommendations by the Worldwide Web Consortium which describes how XML documents can be transformed and rearranged [XSLT], then formatted [XSL] for screen, handheld device, paper or audio presentation.
XSLT
A language for transforming XML documents into other XML documents. [XSLT] is designed for use as part of XSL. See XSL.

Contents

1.3 Strategy

(This section is informative.)

This standard is based primarily on a variety of widely used standards and specifications, including several from the World Wide Web Consortium and the Open eBook Forum. Wherever applicable and appropriate standards or specifications existed they were used. The use of these specifications and technologies is intended to promote a fast and consistent adoption of this standard for the target population, while encouraging its extension into mainstream use.

Contents

1.4 Accessibility Issues

(This section is informative.)

Digital Talking Book files, streams, transformation processes and players have been designed to present their content to people with a wide range of abilities and disabilities. They are designed to allow presentation in forms other than conventional print, due to the inaccessibility of printed documents to these users. To the greatest extent possible, files, streams, transformation processes and players should make information available in as many presentation modes as practical, including human-narrated audio, Braille, synthesized speech and, for players with visual display, large print with user-specifiable size and text re-wrapping, as well as text and audio synchronization and other enhancements for persons with learning disabilities. The controls of players should be easily used by people with a wide range of manual dexterity. Further, tools for producing DTBs should be designed from the outset to be usable by people who are blind, visually impaired, or have other reading disabilities.

During the development of this standard, an advisory document, DTB Playback Device Features List was created. Although it is not a normative part of this standard, player developers may find useful accessibility concepts embodied in it.

In addition to the provisions of this standard, valuable supplemental information is available from the guidelines and techniques produced by the Worldwide Web Consortium's Web Accessibility Initiative. At this time, these documents include:

(This section is normative.)

It is not expected that all modes of presentation will be available in all players and documents, but it is strongly recommended that multiple equivalent presentations be made available to users whenever possible. Historically, products marketed to specific user groups with disabilities have sometimes proven unusable. Not all players need to be accessible to all target groups, but any device compliant with this standard must be accessible to the target group for which it is advertised. It is also strongly recommended that DTB production tools and processes be made accessible to persons with disabilities.

Contents

1.5 Relationship to Other Specifications

This section is informative.

This standard is based on the specific versions of the standards and specifications referenced herein, which are used as defined, except as noted by this document. Any refinement or replacement of a referenced specification by a newer or different version is not directly applicable to this standard. Conformance to this standard is based on the versions of the standards and specifications in effect at the time of this writing.

1.5.1 Relationship to Unicode

This section is normative.

Playback systems must support at least UTF-8 and UTF-16 encodings.

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1.6 Patent Rights

(This section is informative.)

It is possible that compliance with this standard may require the use of one or more inventions covered by patent rights. It is believed that all companies claiming such rights have agreed to grant a license under such rights that they hold on reasonable and nondiscriminatory terms and conditions to any applicant.

Producers of DTB systems or any component thereof are responsible for obtaining the appropriate licenses for any and all technology defined by the relevant standards and specifications referenced by this standard.

Issues surrounding the protection of intellectual property embodied in the works distributed as digital talking books are discussed in section 14, Digital Rights Management.

Contents

1.7 Maintenance Agency

(This section is informative.)

The maintenance agency designated in Appendix 7 will be responsible for reviewing and acting upon suggestions for modifications to this standard. Questions concerning the implementation of this standard and requests for information should be sent to the maintenance agency.

A list of errata relating to this standard will be maintained at http://www.loc.gov/nls/z3986/v100/errata.html.

Contents

2. Overview

(This section is informative.)

A digital talking book (DTB) is a collection of electronic files arranged to present information to the target population via alternative media, namely, human or synthetic speech, refreshable Braille, or visual display, e.g., large print. When these files are created and assembled into a DTB in accordance with this standard, they make possible a wide range of features such as rapid, flexible navigation; bookmarking and highlighting; keyword searching; spelling of words on demand; and user control over the presentation of selected items (e.g., footnotes, page numbers, etc.). Such features enable readers with visual and physical disabilities to access the information in DTBs flexibly and efficiently, and allow sighted users with learning or reading disabilities to receive the information through multiple senses. For a full discussion of these capabilities, see the "Document Navigation Features List" [Navigation Features], developed as the user requirements document on which this standard was based. A document written during the development of this standard, Theory Behind the DTBook DTD [DTBook Theory], also describes the navigational capabilities of a DTB in some detail. The content of DTBs will range from audio alone, through a combination of audio, text, and images, to text alone. Section 13 describes these various types of DTB.

DTB players will also be produced with a variety of capabilities. The simplest might be portable devices with audio-only capabilities. More complex portable players could include text-to-speech capabilities as well as audio output for recorded human speech. The most comprehensive playback systems are expected to be PC-based, supporting visual and audio output, text-to-speech capability, and output to a Braille display. The Playback Device Features List [Player Features] mentioned above presents the committee's priorities for a range of functions across three types of playback device.

The files comprising a DTB fall into ten categories, as described below:

Package File
The Package File, drawn from the Open eBook Publication Structure 1.0.1, contains administrative information about the DTB and the files that comprise it. A valid XML version 1.0 file, it contains a set of metadata describing the DTB, a list (the manifest) of the files that make up the DTB, and a spine that defines the default reading order of the document. See section 3, "Package File."
Textual Content File
A DTB may contain part or all of the text of the document, as an XML 1.0 file marked up in accordance with the document type definition (DTD) defined for this standard, dtbook.dtd. (See Appendix 1, "DTBook DTD.") The textual content file enables properly-configured playback devices to spell words on demand, carry out keyword searches, and permit finely-grained navigation. It may also be accessed directly via refreshable Braille display, synthetic speech, or screen-enlarging software. See section 4, "Content Format for Text."
Audio Files
A DTB may include human or synthetic speech recordings of the document, embodied in audio files encoded in one of a specified group of audio formats. Section 5, "Audio File Formats," presents the formats specified by this standard.
Image Files
In addition to text and audio, DTBs may include images which can be presented on players with visual displays. Section 6, "Image File Formats," lists the formats specified by this standard.
Synchronization Files
To synchronize the different media files of a DTB during playback, this standard specifies the use of the World Wide Web Consortium's (W3C) Synchronized Multimedia Integration Language (SMIL), SMIL 2.0 version, an XML 1.0 application. The DTB SMIL files define a sequence of media events. During each event, text elements and corresponding audio clips as well as any additional visual elements are presented simultaneously. DTB players utilize the synchronization information to both index into the audio presentation and to track, during audio playback, the corresponding position in the textual content file. This standard utilizes a subset of the full SMIL 2.0 specification. See section 7, "Synchronization of Media Files," for discussion of these issues and Appendix 2, "DTB-Specific SMIL DTD," for the DTD that defines the DTB SMIL application.
Navigation Control File
The DTB system supports two modes of navigation, global and local. Global navigation -- movement by structure (chapter, section, subsection) and by other selected points such as pages, figures, or notes -- is effected through the Navigation Control file for XML applications (NCX). The NCX presents a dynamic view of the document's hierarchical structure, allowing the user to move through the document in large steps corresponding to its major divisions, or in progressively smaller steps down to a limit set by the document's detail. Text, audio, and image elements present to the user the document's headings, and id-based links point to the SMIL presentation at the corresponding locations. Appendix 3 contains the XML 1.0 DTD for the NCX. Local (more finely-grained) navigation is not handled by the NCX but is enabled through the textual content file or SMIL file(s), or through time-based movement through the audio presentation, depending on the document and on the player. See section 8, "Navigation Control File (NCX)," and Appendix 3, "NCX DTD" for specifications related to the NCX.
Bookmark/Highlight File
This standard supports user-set, exportable bookmarks and highlights to which text and audio notes may be applied. Specifications for the XML 1.0 file for portable bookmarks and highlights are presented in section 9, "Portable Bookmarks and Highlights" and Appendix 4, "DTD for Portable Bookmarks/Highlights."
Resource File
The resource file contains or references various text segments, audio clips, and/or images that provide alternative representations of navigational information -- for example, feedback on the user's current location in the document. It supplies information normally presented in a print book via typographical clues. See section 10, "Resource File," and Appendix 5, "DTD for Resource File" for file specifications.
Distribution Information File
Given the great size of audio files, even when heavily compressed, it will be common for large books to span several media units. Section 11, "Packaging Files for Distribution," describes how the "distInfo" file maps the location of each SMIL file to a specific media unit, e.g., disk 1 of 3. It also explains how, when several books are distributed on the same media unit, the distInfo file stores information about each book for presentation to the reader . Appendix 6, "Distribution Information DTD," presents the document type definition for "distInfo" files.
Presentation Styles
Section 12, "Presentation Styles," discusses how the presentation of a DTB in various media may be controlled through the use of optional style sheets.

Contents

3. The DTB Package File

(This section is normative.)

A DTB conforming to this standard must include exactly one Package File which must be a valid XML 1.0 document conforming to the Open eBook Forum™ (OEBF) 1.0.1 package DTD (oebpkg101.dtd) and its associated entity reference (oeb1.ent). The full specification, DTD, and entity reference for the OEBF package file are available for download from the OEBF site [OEBF]. The Package File must be named with the extension ".opf."

A Package File conforming to this standard must comply with all aspects of section 2 of the OEBF Publication Structure 1.0.1, with the following two exceptions:

(This section is informative.)

The Package File, drawn from the OEBF Publication Structure 1.0.1, contains administrative information about the DTB, the files that comprise it, and how these files interrelate. This section, drawn largely from the Publication Structure, provides only a brief summary of the function of each section with an example illustrating how it is applied to the DTB. Please see section 2 of the full OEBF Publication Structure 1.0.1 for complete details on the Package File.

The Publication Structure describes the major parts of the Package File as follows:

Here is an informal outline of the package file:

<?xml version="1.0"?>
<!DOCTYPE package PUBLIC "+//ISBN 0-9673008-1-9//DTD OEB 1.0.1 Package//EN"
"http://openebook.org/dtds/oeb-1.0.1/oebpkg101.dtd">
          
<package>
         <metadata>...</metadata>
         <manifest>...</manifest>
         <spine>...</spine>
         <tours>...</tours>
         <guide>...</guide>
</package>

3.1 Package Identity

(This section is normative.)

The package must include a value for its unique-identifier attribute. This is required because more than one dc:Identifier may be present in a DTB's Package File metadata and the unique-identifier specifies which dc:Identifier element provides the package's primary identifier. The value of unique-identifier must match the id attribute of one and only one dc:Identifier element which is a descendant of the package element.

The primary identifier of the DTB must be globally unique.

(This section is informative.)

Example 3.1:


     
<package unique-identifier="uid">
    <metadata>
        <dc-metadata...>
            <dc:Identifier id="uid" scheme="DTB">uk-rnib-db02006</dc:Identifier>
...
</package>

3.2 Publication Metadata

(This section is normative.)

This portion of the Package File contains the information about a DTB that would normally be found in a library catalog record. It includes data about the DTB itself (e.g., title, author, producer, format, and narrator) as well as information about the source publication (usually a print book) such as publisher, edition, copyright statement, etc.

The Package File must contain exactly one metadata element which must contain one and only one dc-metadata element holding Dublin Core [DC] metadata and must contain supplemental metadata in an x-metadata element. The x-metadata element must contain at least one instance of the meta element, which uses name and content attributes to define its value (see section 3.2.3, "X-Metadata").

3.2.1 Dublin Core Metadata

(This section is normative.)

The use of Dublin Core metadata within a compliant DTB must conform to the following description from the OEBF Publication Structure 1.0.1:

The dc-metadata element contains specific publication-level metadata as defined by the Dublin Core initiative (http://purl.org/dc/). The descriptions below are included for convenience, and the Dublin Core's own definitions take precedence (see http://www.ietf.org/rfc/rfc2413.txt).

The dc-metadata element can contain any number of instances of any Dublin Core elements. Dublin Core element names begin with the "dc:" prefix followed by a leading uppercase letter. Dublin Core metadata elements may occur in any order; in fact, multiple instances of the same element type (multiple dc:Creator elements, for example) can be interspersed with other metadata elements without change of meaning.

For upwards-compatibility, the element metadata in an OEB package is required to have an attribute of xmlns:dc="http://purl.org/dc/elements/1.0/" and xmlns:oebpackage="http://openebook.org/namespaces/oeb-package/1.0/".

Following are brief definitions of the Dublin Core elements. See the Publication Structure and the Dublin Core itself for more complete descriptions. The attributes "xml:lang" and "id" can be applied to all "dc:..." elements. Additional attributes can be used with several elements as detailed below. Note that all Dublin Core element types may be repeated (occur more than once) within dc-metadata.

3.2.2 DTB ID Scheme

(This section is informative.)

Various schemes are available for identifying digital publications. In the DTB domain, the requirements for an identifier are simply to identify the publication in a manner that is highly likely to be globally unique. A major purpose of the uniqueness requirement is to prevent filename collisions among bookmark files.

To meet this base requirement, a simple DTB id scheme may be used. A DTB identifier under this scheme consists of a hyphen-separated string consisting of a two-letter country code drawn from [ISO 3166], an agency code unique within its country, and an identifier unique within the agency. For example, us-afb-x12345.

This scheme will provide a simple solution to the uniqueness requirement that will serve DTB-publishers' needs in the short term. In the longer term, as the requirements of a global library of alternative format materials become more important, other more sophisticated mechanisms should certainly be employed.

3.2.3 X-Metadata

(This section is normative.)

The following names were developed for the DTB application to supply information that the Dublin Core element set does not cover. These names may appear only within the x-metadata containing element, as values of the name attribute on the meta element. Each x-metadata name below is shown as either "Repeatable" (it may be used more than once) or "Not repeatable."

(This example is informative)

Example 3.2:


...
<metadata> 
     <dc-metadata xmlns:dc="http://purl.org/dc/elements/1.0/"
     xmlns:oebpackage="http://openebook.org/namespaces/oeb-package/1.0/">
          <dc:Title>Revised Standards and Guidelines of
          Service for the Library of Congress Network of Libraries for the 
          Blind and Physically Handicapped 1995</dc:Title>
          <dc:Subject>library information networks</dc:Subject> 
          <dc:Subject>libraries and the physically
          handicapped--standards--U.S.</dc:Subject>
          <dc:Subject>libraries and the blind--standards--U.S.</dc:Subject> 
          <dc:Identifier id="uid" scheme="DTB">us-nls-db00001</dc:Identifier>
          <dc:Identifier  scheme="DOI">10.1000/DX44998</dc:Identifier>
          <dc:Creator role="aut">American Library Association. Association of 
          Specialized and Cooperative Library Agencies</dc:Creator>
          <dc:Publisher>National Library Service for the Blind and Physically
          Handicapped, Library of Congress</dc:Publisher>
          <dc:Date>2000-06-22</dc:Date>
          <dc:Source>0-8389-7797-9</dc:Source>
          <dc:Language>en</dc:Language>
          <dc:Format>ANSI/NISO Z39.86-200x v1.0.0</dc:Format>
          <dc:Description>A document developed to improve library service for blind and
          physically disabled persons by providing a tool for assessing the current status of those services
          and for developing long-range plans.</dc:Description>
     </dc-metadata>
     <x-metadata>
          <meta name="dtb:sourceDate" content="1995" />  
          <meta name="dtb:sourcePublisher" content="American Library Association" />
          <meta name="dtb:sourceRights" content="copyright 1995, American Library Association" />
          <meta name="dtb:narrator" content="Lowenstein, Ralph" />
          <meta name="dtb:producer" content="American Foundation for the Blind" />
          <meta name="dtb:multimediaType" content="audioNcx" />
          <meta name="dtb:totalTime" content="06:22:34.143" />
     </x-metadata>

</metadata>
...

3.3 Manifest

(This section is normative.)

The manifest, which is a child of the package element, must contain a complete list of all of the files (documents, audio files, images, style sheets, etc.) that make up a given DTB, including the package file itself. The distInfo file and any associated audio changeMsgs are not considered part of the DTB and thus shall not be listed (See section 11, "Packaging Files for Distribution.") Each file is referenced by an item element. Each item must have an href attribute which is the URI of the referenced file and is unique within the manifest. This URI must not include fragment identifiers; if relative, it is interpreted as relative to the package file itself. Further, any relative URIs contained within an XML file listed in the manifest are considered to be relative to the referring file.

In addition, each item must have a media-type attribute containing the MIME media type of the file, and an id attribute. The id is utilized primarily when a manifest item is referenced by the spine. The manifest also includes fallback declarations for files of types not supported by this standard (see OEBF Publication Structure for details). Support for the fallback mechanism is not required by this standard. The NCX entry in the Package File manifest must have an id value equal to "ncx". The Resource File entry in the Package File manifest must have an id value equal to "resource". The item elements listing SMIL files in the manifest must have a media-type attribute of "application/smil". The item elements for the NCX, textual content file(s), Package File, and Resource File must have media-type attribute values of "text/xml." The order of item elements within the manifest is not significant.

(This example is informative)

A sample manifest for a DTB with audio, structure, and text follows (multimediaType=audioFullText):

Example 3.3:


...
<manifest>
     
     <item id="opf" href="rs.opf" media-type="text/xml" />
     <item id="text" href="rs.xml" media-type="text/xml" />
     <item id="text_style" href="dtbbase.css" media-type="text/css2" />
     <item id="ncx" href="rs.ncx" media-type="text/xml" />
     <item id="ncx_style" href="ncx16.css" media-type="text/css2" /> 
     <item id="SMIL" href="rs.smil" media-type="application/smil" /> 
     <item id="foreword" href="rs_fwdx.mp3" media-type="audio/mp3" />
     <item id="standards" href="rs_stdx.mp3" media-type="audio/mp3" />
     <item id="appendices" href="rs_app.mp3" media-type="audio/mp3" />
     <item id="index" href="rs_index.mp3" media-type="audio/mp3" />
     <item id="fig_01" href="fig1.png" media-type="image/png" />
     <item id="resource" href="rs.res" media-type="text/xml" />
     <item id="resource_audio" href="res.mp3" media-type="audio/mp3" />


</manifest>
...

Here is a manifest for an audio-only version of the above DTB (multimediaType=audioNcx), where separate SMIL files were created for each segment of the book.

Example 3.4:


...
<manifest>
     <item id="opf" href="rs.opf" media-type="text/xml" />
     <item id="ncx" href="rs.ncx" media-type="text/xml" /> 
     <item id="foreword" href="rs_fwdx.mp3" media-type="audio/mp3" />
     <item id="standards" href="rs_stdx.mp3" media-type="audio/mp3" />
     <item id="appendices" href="rs_app.mp3" media-type="audio/mp3" />
     <item id="index" href="rs_index.mp3" media-type="audio/mp3" />
     <item id="SMIL1" href="rsfwd.smil" media-type="application/smil" />
     <item id="SMIL3" href="rsapp.smil" media-type="application/smil" />
     <item id="SMIL4" href="rsind.smil" media-type="application/smil" /> 
     <item id="SMIL2" href="rsstd.smil" media-type="application/smil" /> 

</manifest>
...

3.4 Spine

(This section is normative.)

The spine, a child of the package element, shall consist of a list of one or more itemref elements whose order defines the default linear reading order for the DTB. Each itemref must contain an idref which points to the id of a SMIL file listed in the manifest. Only SMIL files can be referenced by itemrefs in the spine. The itemrefs must be listed in the spine in order in which the SMIL files are to be presented. A player must consult the spine when it reaches the end of a SMIL file to determine which file to render next.

(The following examples are informative.)

The first of the following examples shows the spine that corresponds to the first of the two manifest examples above:
Example 3.5:


<spine>

     <itemref idref="SMIL" />

</spine>

The following spine matches the second manifest example above. The correct reading order is presented here. Note that it does not match the order of files in the manifest, where order is not significant.

Example 3.6:


<spine>

      <itemref idref="SMIL1" /> 
      <itemref idref="SMIL2" />
      <itemref idref="SMIL3" />
      <itemref idref="SMIL4" /> 

</spine>

3.5 Tours

(This section is normative.)

Compliant players are not required to support tours.

(This section is informative.)

The tours element is an optional child of the package element. The OEBF Publication Structure describes tours as follows: "Much as a tour guide might assemble points of interest into a set of sightseers' tours, a content provider may assemble selected parts of a publication into a set of tours to enable convenient navigation. ... Reading systems may use tours to provide various access sequences to parts of the publication, such as selective views for various reading purposes, reader expertise levels, etc." Because of inherent differences between the structures of a DTB and the OEBF tours, it is not feasible to implement tours in a DTB prepared in accordance with this standard. If a producer wishes to provide the functionality described above, it may partially achieve it by producing customized navLists in the NCX.

3.6 Guide

(This section is normative.)

Compliant players are not required to support guides.

(This section is informative.)

As specified in the OEBF Publication Structure, the guide, a child of the package element, lists the key structural features of the DTB, such as the table of contents, introduction, bibliography, etc. to enable playback devices to provide convenient access to them. Because DTBs include a mandatory NCX that satisfies a more rigorous and detailed access requirement, the guide is not expected to be used in DTBs.

Contents

4. Content Format for Text

4.1 Introduction

(This section is normative.)

This standard defines an XML 1.0 Document Type Definition -- DTBook -- for markup of the textual content files of books and other publications presented in digital talking book format. To be compliant with this standard, a textual content file of a DTB must be a valid XML file conforming to dtbook100.dtd, which can be found in Appendix 1, "DTBook DTD." The version attribute on the dtbook element must be present and contain the value drawn from the above-named DTD. Parsers will not enforce the presence of this attribute, so other mechanisms must.

A DTB that includes textual content will, in most cases, contain only one textual content file. However, when necessary (with a very large book, for example), a DTB can contain multiple textual content files, each of which must be valid to the DTBook DTD.

DTB content producers may extend the base DTD by including one or more new elements or full modules for special situations. To remain conformant with this standard, such extensions of the DTD must employ the mechanisms specified by XML 1.0. See section 4.2.2, "Modular Extension of the DTD."

4.2 Using the DTBook Element Set

(This section is informative.)

A document developed during the creation of this standard, Theory Behind the DTBook DTD [DTBook Theory], discusses the rationale underlying the DTBook element set and the benefits it provides to digital talking book applications.

An alphabetical listing of the DTBook elements, with definitions, is included in section 4.3. Two documents external to this standard provide detailed information on the use of the element set. First, an expanded version of the DTD, in HTML format, (see [DTBook HTML]) provides full detail on each element, describing where it can be used and which elements can be used within it, along with an expanded list of attributes.

Second, a comprehensive set of guidelines for applying DTBook markup is available from the DAISY Consortium. These Structure Guidelines [StructGuide] describe the correct application of the DTBook element set, emphasize the importance of capturing the structure of the text content, and provide detailed examples of the use of all DTBook elements.

The DTBook element set has considerable application outside of the digital talking book as well. It was designed to enable the production of documents in a variety of accessible formats. At least one U.S. Braille translation software package has implemented a facility that imports DTBook documents and automatically translates and formats them in Grade 2 Braille. It is expected that similar automated processes will be developed for converting properly marked-up documents into large print and for rendering DTBook documents in Braille, synthetic speech, and large print "on the fly." Finally, an attribute called "showin" is incorporated in the DTBook element set to control the display of selected segments of a DTBook document. For example, descriptions of a graph might vary between Braille and large print editions; "showin" could allow only the appropriate version to show in each edition, although both would be present in the DTBook document.

This standard does not mandate the degree of markup to be applied to a textual content file. However, the richer the markup, the greater the functionality available to the reader.

For more information on XML 1.0 markup and DTD usage, see the W3C XML site [XML].

4.2.1 DTBook Markup Related to SMIL

(This section is normative.)

To ensure efficient player operation with DTBs containing textual content files, the smilref attribute must be present and non-empty for each element in the textual content file referenced by a SMIL file. The smilref value shall normally be the uri of the SMIL time container (par or seq) containing the media object that references a given element. However, in a text-only DTB consisting of a sequence of text media objects, smilref contains the uri of the media object that references the element. The smilref attribute permits the DTB player to resume SMIL-based playback following text-based navigation, full-text searches, etc.

4.2.2 Modular Extension of the DTD

(This section is informative.)

The DTBook DTD includes a base set of elements for use in marking up a broad range of material. Additional modules containing elements for specialized applications such as poetry, plays, dictionaries, mathematics, etc. can be "invoked" from within a DTBook document when needed, as described below.

A DTBook document is an XML application. Therefore it should begin with the XML declaration identifying the version of XML, and the optional character set encoding (see Appendix 1, "DTBook DTD" for more information):

<?xml version="1.0" encoding="UTF-8" ?>

This is followed by the document type declaration:


<!DOCTYPE dtbook SYSTEM "dtbook100.dtd"
>

For discussion of other ways of expressing the DOCTYPE, see section 2.2 of Appendix 1, "DTBook DTD."

A book can invoke other DTDs or modules to augment the DTBook DTD by adding instructions in square brackets before the concluding ">" of the document type declaration. Such instructions in square brackets are called the "internal subset of declarations." For example:


<!DOCTYPE dtbook SYSTEM "dtbook100.dtd"
        [
            <!ENTITY % dramaModule SYSTEM "drama.dtd" >
            %dramaModule;
            <!ENTITY % externalblock "| drama">
            <!ENTITY % externalinline "| stagedir">
        ]> 

The first line of the internal subset declares an entity known as "dramaModule" and provides the URI where that module can be found. The second line invokes this entity, that is "brings it into" the current document, just as the DOCTYPE declaration invoked the base DTD (dtbook100.dtd). The third line declares the entity "% externalblock" and gives it the value "drama." Since dtbook100.dtd contains an entity of the same name, and the internal subset overrules the base (external) DTD (dtbook100.dtd) in areas of conflict, everywhere in dtbook100.dtd where %externalblock; appears (that is, wherever block elements are allowed), the value "drama" is added. Since drama is the root element in the drama module, the full drama module can be used there. Similarly, the last line effectively allows the element stagedir to be used anywhere %externalinline; is allowed in dtbook100.dtd (wherever inline elements can be used).

More than one module may be needed and included in a book. In the following example, both a poetry and drama module are invoked, as well as one inline element (stagedir) from the drama module.


        [ 
            <!ENTITY % poemModule "http://www.xyz.org/poem.dtd" >
            %poemModule;
            <!ENTITY % dramaModule "http://www.xyz.org/drama.dtd" >
            %dramaModule;
            <!ENTITY % externalblock "| poem | drama" >
            <!ENTITY % externalinline "| stagedir">
        ]>

See section 3 of Appendix 1, "DTBook DTD" for a more detailed discussion of this issue.

4.3 DTBook Elements

(This section is informative.)

The element names from DTBook are listed below in alphabetical order. The description provided for each element is taken directly from the DTBook DTD.

a
contains an anchor, which is used to reference another location, within the same or another <dtbook>.
abbr
designates an abbreviation, a shortened form of a word. For examples: Mr., approx., lbs., rec'd.
acronym
marks a word formed from key letters (usually initials) of a group of words. For examples: UNESCO, NATO, XML.
address
contains a location at which a person or agency may be contacted. By use of <line> to contain content of the individual lines, the class attribute can be used to identify the content of that <line>. For example, class values might include: name, address, region: (state. province, etc.), country, location code: (zipcode, provincial code, etc.), phone, fax, email, etc.
annoref
marks a text segment that references an <annotation>. Each <annoref> is usually a word, phrase, or whole line that is part of the surrounding text (identified in the original print book by bolding, italics, etc.). It should not normally be allowed to be turned off in a DTB application.
annotation
is a comment on or explanation of a portion of a printed book. It differs from <note> in that an <annotation> is usually set in the margin or on a facing page, often with no explicit reference to it inserted in the text. Any local reference to <annotation id="xxx"> is by <annoref idref="#xxx">.
author
identifies the writer of a work other than this one. Contrast with <docauthor> which identifies the author of this work. <author> typically occurs within <blockquote> or <cite>.
bdo
is used in special cases where the automatic actions of the bi-directional algorithm would result in incorrect display.
blockquote
indicates a block of quoted content that is set off from the surrounding text by paragraph breaks. Compare with <q> which marks short, inline quotations.
bodymatter
consists of the text proper of a book, as opposed to preliminary material <frontmatter> or supplementary information <rearmatter>.
book
surrounds the actual content of the document, which is divided into <frontmatter>, <bodymatter>, and <rearmatter>. <head>, which contains metadata, precedes <book>.
br
marks a forced line break.
caption
describes a <table> or <img>. If used with <table> it must follow immediately after the <table> start tag. If used with <img> or <imggroup> it is not so constrained.
cite
marks a reference (or citation) to another document. <cite> may occur within an <a href="URL">...</a> should that other document be available in the same dtbook distribution.
code
designates a fragment of computer code.
col
is a means to apply attribute values to a column of a <table>.
colgroup
groups adjacent columns <col> that are semantically related. The <col> in a <colgroup> may inherit attribute values from it, or an enclosing parent, such as <thead>, <tfoot>, or <tbody>, or within a <table>.
dd
marks a definition of a term within a definition list.
dfn
marks the first occurrence of a word or term that is defined or explained there or elsewhere in <book>. Often <dfn> is rendered in italics, sometimes in parentheses.
div
is a generic container for subdivisions of a book. The <level1> ... <level6> hierarchy, or the <level> tag used recursively, should mark the major hierarchical structures of a book, while <div> is used in less formal circumstances or when for production purposes it is desired that a structure should be treated differently. The class attribute value identifies the actual name (e.g., part, chapter, letter) of the structure it marks. Compare with <span> which is used in inline settings.
dl
contains a definition list, usually consisting of pairs of terms <dt> and definitions <dd>. Any definition can contain another definition list.
docauthor
marks each author or editor of this work. Compare with <author>, used to mark the author of another work, within <blockquote> or <cite>.
doctitle
marks the title of the book within <frontmatter>. By convention it should appear only once, usually first. Within <head> is <title> whose contents are generally the same.
dt
marks a term in a definition list.
dtbook
is the root element in the Digital Talking Book DTD. <dtbook> contains metadata in <head> and the contents itself in <book>.
em
indicates emphasis. Usually <em> is rendered in italics. Compare with <strong>.
frontmatter
contains preliminary material enclosed in appropriate <level> or <level1>. Content may include <doctitle>, <docauthor> copyright notice, foreword, acknowledgments, table of contents, etc. <frontmatter> serves as a guide to the content and nature of a <book>.
h1
contains the text of the heading for a <level1> structure.
h2
contains the text of the heading for a <level2> structure.
h3
contains the text of the heading for a <level3> structure.
h4
contains the text of the heading for a <level4> structure.
h5
contains the text of the heading for a <level5> structure.
h6
contains the text of the heading for a <level6> structure.
hd
marks the text of a heading in a <list> or <sidebar>.
head
contains metainformation about the book but no actual content of the book itself, which is placed in <book>. This information is consonant with the <head> information in xhtml, see [XHTML11STRICT]. Other miscellaneous elements can occur before and after the required <title>. By convention <title> should occur first.
hr
is an empty element indicating a horizontal rule. May be used to indicate a break in the text where only blank lines, a row of asterisks, a horizontal line, etc. are used in the print book.
img
marks a visual image. An <img> will generally contain a longdesc, a pointer to the related <prodnote>. The referencing is typically of the form <caption imgref="#yyy">The Caption</caption> for the printed caption of the <img id="yyy">.
imggroup
provides a container for <img> or images and associated <caption> and <prodnote>. <prodnote> may contain a description of the image. The content model allows: 1) multiple <img> if they share a caption, with the ids of each <img> in the <caption idref="id1 id2 ...">, 2) multiple <caption> if several captions refer to a single <img id="xxx"> where each caption has the same <caption idref="xxx">, 3) multiple <prodnote> if different versions are needed for different media (e.g., large print, braille, or print.)
kbd
designates information that the reader is to input directly into a computer using the keyboard.
level
is an alternative tag for marking the major structures in a book. It may be used recursively, i.e., repeated indefinitely with each successive occurrence nesting within the previous. It may also be included in a subsequent higher level. Subordinate levels have greater depth. Contrast with the explicit <level1>...<level6> elements, which may not be intermixed with <level>.
level1
is the highest level container of major divisions of a book. Used in <frontmatter>, <bodymatter>, and <rearmatter> to mark the largest divisions of the book (usually parts or chapters), inside which level2 subdivisions (often sections) may nest. The class attribute identifies the actual name (e.g., part, chapter) of the structure it marks. Contrast with <level>.
level2
contains subdivisions that nest within <level1> divisions. The class attribute identifies the actual name (e.g., subpart, chapter, subsection) of the structure it marks.
level3
contains sub-subdivisions that nest within <level2> subdivisions (e.g., sub-subsections within subsections). The class attribute identifies the actual name (e.g., section, subpart, subsubsection) of the subordinate structure it marks.
level4
contains further subdivisions that nest within <level3> subdivisions. The class attribute identifies the actual name of the subordinate structure it marks.
level5
contains further subdivisions that nest within <level4> subdivisions. The class attribute identifies the actual name of the subordinate structure it marks.
level6
contains further subdivisions that nest within <level5> subdivisions. The class attribute identifies the actual name of the subordinate structure it marks.
levelhd
contains the text of a heading within <level>. Corresponds to <h1> through <h6> used in <level1> through <level6>.
li
marks each list item in a <list>. <li> content may be either inline or block and may include other nested lists. Alternatively it may contain a sequence of list item components, <lic>, that identify regularly occurring content, such as the heading and page number of each entry in a table of contents.
lic
("list item component") allows ordered substructure within a list item <li>. Used when a list item is made up of two or more components, as in a table of contents entry. The same number of <lic> should occur in each <li>. If not, correspondence of <lic> in different <li> is in order of occurrence for the current writing direction of the <li>.
line
marks a single logical line of text. Often used in conjunction with <linenum> in documents with numbered lines.
linenum
contains a line number in, for example, in legal text.
link
is an empty element appearing in the <head> section of a document that establishes a connection between the current document and another document. The <link> element conveys relationship information (for example, "next" and "previous") that may be rendered by user agents in a variety of ways.
list
contains some form of list, ordered or unordered. The list may have intermixed heading <hd> (generally only one, possibly with <prodnote>) and an intermixture of list items <li> and <pagenum>. If bullets and outline enumerations are part of the print content, they are expected to prefix those list items in content, rather than be implicitly generated. Note: XHTML has explicit list element types: ol for ordered, and ul for unordered.
meta
indicates metadata about the book. It is an empty element that may appear repeatedly only in <head>.
note
marks a footnote, endnote, etc. Any local reference to <note id="yyy"> is by <noteref idref="#yyy">.
noteref
marks one or more characters that reference a footnote or endnote <note>. Contrast with <annoref>. Either may be independently skippable.
notice
contains a warning, caution, or other type of admonition normally found in the margin of a book. In contrast with <sidebar> a <notice> must be presented at a specific location within the text. Its presentation is not optional.
p
contains a paragraph, which may contain subsidiary <list> or <dl>.
pagenum
contains one page number as it appears from the print document, usually inserted at the point within the file immediately preceding the first item of content on a new page.
prodnote
contains language added to the alternative-format version by the producer; commonly used to: 1) provide descriptions of one or more visual elements such as charts, graphs, etc. 2) supply operating instructions 3) describe differences between the print book and the audio version.
q
contains a short, inline quotation. Compare with <blockquote> which marks a longer quotation set off from the surrounding text.
rearmatter
contains supplementary material such as appendices, glossaries, bibliographies, and indices. It follows the <bodymatter> of the book.
samp
contains a sample of work created by the author for use as an example or template. For example, a sample business letter, resume, or computer program output, or form.
sent
marks a sentence.
sidebar
contains information supplementary to the main text and/or narrative flow and is often boxed and printed apart from the main text block on a page. It may have a heading <hd>.
span
is a generic container for use in inline settings when no specific tag exists for a given situation. The class attribute may describe the nature of the text it marks (e.g., a typographical error). May be used to mark a class of items to which styles are to be applied. Compare with <div> which is used in block settings. #PCDATA following an inline can be given an id for resumed playing by putting it in a <span>.
strong
marks stronger emphasis than <em>. Visually <strong> is usually rendered bold.
style
provides the means to include styling information that applies to the book. It may appear only in <head>. It may include CDATA sections.
sub
indicates a subscript character (printed below a character's normal baseline). Can be used recursively and/or intermixed with <sup>.
sup
marks a superscript character (printed above a character's normal baseline). Can be used recursively and/or intermixed with <sub>.
table
contains cells of tabular data arranged in rows and columns. A <table> may have a <caption>. It may have descriptions of the columns in <col>s or groupings of several <col> in <colgroup>. A simple <table> may be made up of just rows <tr>. A long table crossing several pages of the print book should have separate <pagenum> values for each of the pages containing that <table> indicated on the page where it starts. Note the logical order of optional <thead>, optional <tfoot>, then one or more of either <tbody> or just rows <tr>. This order accommodates simple or large, complex tables. The <thead> and <tfoot> information usually helps identify content of the <tbody> rows, For a multiple-page print <table> the <thead> and <tfoot> are repeated on each page, but not redundantly tagged.
tbody
marks a group of rows in the main body of a <table>. If the <table> is divided into several sections, each consisting of a number of rows, each section would be separately tagged with <tbody>. The same <thead> and <tfoot> apply to every <tbody> section.
td
indicates a table cell containing data.
tfoot
marks footer information in a <table>, consisting of one or more rows <tr>, usually of <th> cells. On multiple-page printed tables, <tfoot> rows are repeated at the bottom of the first page of the <table> and its continuation on other pages.
th
indicates a table cell containing header information.
thead
marks header information in a <table>, consisting of one or more rows <tr> of <th> cells. On multiple-page printed tables, <thead> rows are repeated at the top of the <table> and on top of its continuation on other pages.
title
contains the title of the book but is used only as metainformation in <head>. Use <doctitle> within <book> for the actual book title, which will usually be the same.
tr
marks one row of a <table> containing <th> or <td> cells. The values for %cellhalign; and %cellvalign; provide default values for <th> and <td> in the row, overriding any from <col>.
w
marks a word.

Contents

5. Audio File Formats

5.1 Distribution Formats

(This section is normative.)

A set of audio file formats is listed below. A compliant audio player must be capable of decoding at least one of the formats listed. It is strongly recommended that players be able to decode all listed formats. Content compliant with this standard must be delivered in one of the formats below, or any mixture of them. The file extensions shown for each format must be utilized in audio filenames in compliant DTBs. Values are not case-sensitive.

It is permissible for parts of a single book to be encoded in different audio formats. For example, a producer may choose to encode a lengthy bibliography at a lower bitrate or with a different codec than the main body of the book. Players must support transitions between differently encoded sections smoothly. There is no restriction on the granularity of these parts, i.e. they may occur at any point in the SMIL presentation.

Support for multi-channel rendering is not required. Stereo signals must be recognized and rendered at least in monaural format.

A compliant DTB player that provides audio output should be capable of decoding the following audio formats:

While the ISO standards for MP3 and AAC require support for variable bitrate playback, players compliant with this standard are only required to support constant bitrate playback.

Players must support sample rates of 44.1, 22.05, and 11.025 kHz at a depth of 16 bits per sample. Compressed audio must be encoded such that the output sampling rate is restricted to one of the above three rates.

5.2 Formats for Audio Notes

(This section is normative.)

Audio players capable of recording and exporting audio notes for bookmarks and highlights must support encoding in the following format or one of the formats specified in section 5.1. Audio players capable of importing bookmarks and highlights must support decoding of the following format.

Contents

6. Image File Formats

(This section is normative.)

Images included in DTBs must be presented in one or more of the following formats. Compliant playback devices that support image display must be capable of displaying the following image formats: JPEG (JFIF V 1.02) [JPEG] and PNG [RFC 2083]. Support for Scalable Vector Graphics [SVG] is recommended. Appendix 8 of the SVG specification addresses accessibility issues.

Contents

7. Synchronization of Media Files

7.1 Introduction

7.1.1 Background

(This section is informative.)

The Synchronized Multimedia Integration Language (SMIL 2.0) [SMIL] was developed by the World Wide Web Consortium as a standard for definition and playback of multimedia presentations over the Internet. SMIL defines the sequence of playback for one or more media objects. In the case of DTBs, the primary media objects are audio and textual content files; SMIL provides for their parallel and synchronized presentation. Any DTB constructed using SMIL, and utilizing content encoded in standard text and audio media types, is playable on any device or platform which has implemented a SMIL-conformant player of the same or later SMIL version, so long as the necessary audio and textual rendering decoders are present.

What distinguishes a DTB playback system from a basic SMIL player is the inclusion of specific navigation and presentational capabilities set out in the user requirements for DTBs ([Navigation Features]). These capabilities can utilize information from an NCX file, from the textual content, and/or from the SMIL file itself. The key to this information is the inclusion of unique identifiers within the textual content (when present) and SMIL files. Audio files are indexed by time-based positions and in themselves contain no embedded semantic structure. To provide semantic structure to audio content, it is necessary to associate time-points in the audio file with the corresponding position within the textual content. This is achieved using SMIL through the pairing of a pointer to a specific position within a textual content file (referenced by a URI) with its corresponding time position in the audio content. In the case of the DTB SMIL application, each synchronization point within the SMIL file is assigned a unique identifier. The presence of these identifiers within both the textual content and the SMIL allows navigation to occur by several different methods, as determined by the playback system.

SMIL incorporates a control structure called customTests, which allows SMIL authors to identify by class selected elements of a document (e.g., notes, page numbers, line numbers). The playback device can then expose to the user the presence of these classes and allow the user to select whether a given class of elements is to be read or skipped over during sequential playback.

The DTB producer determines granularity of the synchronization events. Synchronization events may be limited to the primary structural elements (those indicated in the NCX) or may be augmented in books with full textual content to include synchronization down to paragraph, sentence, or even word level. The requirement for this level of synchronization is that the textual content include mark-up tags for the desired elements, and that those elements include unique identifiers that can be referenced in the SMIL files.

The SMIL file for a DTB typically will consist of a sequence of parallel events (e.g., text and audio (and possibly image) events occurring simultaneously). SMIL represents this structure through the use of the "time containers" seq (sequence of media objects) and par (parallel time grouping in which multiple media objects play back at the same time). A simple form of DTB SMIL file would be as follows, where the three pars shown are played one after the other, and the text and audio content referenced in each par are rendered simultaneously:


<smil>
 ...
<seq>
<par><text.../><audio.../></par>
<par><text.../><audio.../></par>
<par><text.../><audio.../><img.../></par>
</seq>
...
</smil>

7.1.2 SMIL Modules

(This section is informative.)

Synchronization of media objects in this standard is based on the SMIL 2.0 Specification. Developers are requested to reference SMIL 2.0 [SMIL] for complete background and details. Only a small subset of the SMIL specification is utilized in this implementation, drawing from the following modules, which are grouped by functional area. Modules marked with asterisks are used in whole or in part in this application; the others are not utilized but are included because they are part of a core set of modules required for host language conformance under W3C modularization guidelines.

The modules mentioned above can be combined, using W3C modularization guidelines, to form a profile specific to DTB applications. Section 2 of the SMIL specification, "The SMIL 2.0 Modules," describes this process in detail.

7.2 Application of SMIL to DTBs

(This section is normative.)

To simplify validation using commonly available parsers and to lessen the complexity of determining content models and applicable attribute lists, a DTB-Specific SMIL DTD is included in this standard in Appendix 2. This DTD includes only those elements and attributes from the modules listed above that are required for the DTB application. In addition, it is more restrictive than the SMIL modules in that id attributes are often required in the DTB application when they are implied in the SMIL modules.

A compliant DTB must contain at least one SMIL file. All SMIL files included in a DTB must be valid XML documents conforming to dtbsmil100.dtd. The version attribute on the smil element must be present and contain the value drawn from the above-named DTD. Parsers will not enforce the presence of this attribute, so other mechanisms must.

Time containers (seqs or pars) within SMIL files must contain ids. Media objects (audio, text, and img) may also contain ids, although this practice will generally be limited to single-medium DTBs. See section 7.4.11, "Text-Only DTBs."

In the textual content file, each segment to be synchronized (e.g., heading, paragraph, list item, etc.) must be contained within an element carrying a unique id to which the corresponding SMIL segment points. In addition, any textual content file element referenced by a SMIL file must include a smilref attribute specifying the uri of the time container or media object that references it. The smilref value shall normally be the uri of the SMIL time container containing the media object that references a given element. However, in a text-only DTB consisting of a sequence of text media objects, smilref shall contain the uri of the referencing media object itself. See section 4.2.1, "DTBook Markup Related to SMIL."

To ensure efficient player operation with DTBs containing textual content files, the smilref attribute must be present and non-empty for each element in the textual content file referenced by a SMIL file. The smilref value shall normally be the uri of the SMIL time container (par or seq) containing the media object that references a given element. However, in a text-only DTB consisting of a sequence of text media objects, smilref contains the uri of the media object that references the element. The smilref attribute permits the DTB player to resume SMIL-based playback following text-based navigation, full-text searches, etc.

It is strongly recommended that the SMIL file(s) have a level of granularity matching that of the textual content file. That is, if the textual content file is marked up to the paragraph level, the SMIL file(s) should include synchronization to the paragraph level.

All time offsets in SMIL files (and all other applicable DTB files, e.g., NCX clipBegin/clipEnd, bookmark timeOffsets, etc.), are based on normal play speed. In order to maintain synchronization, a player must process time offsets independently of actual playback speed.

7.3 SMIL Elements

(This section is informative.)

As mentioned above, the DTB application utilizes only a portion of the elements and attributes that make up the modules in the DTB SMIL Profile. Playback devices compliant with this standard need support only the following SMIL elements and attributes, which make up the DTB-Specific SMIL DTD.

7.3.1 Core Attributes

(This section is informative.)

The following attributes are allowed when the entity %Core.attrib; is listed above:

7.4 SMIL Requirements for DTBs

7.4.1 "Escapable" Structures

(This section is normative.)

DTB players should provide the functionality to allow readers to escape from the DTB rendition of specific structures (at a minimum tables, lists, producer's notes, annotations, and notes) with a single action. To support this functionality, any such structure consisting of multiple time containers (i.e., seqs and pars) must be wrapped in a seq. In addition, a class attribute must be applied to the seq or par containing a table, list, annotation, or note, using element names drawn from the DTBook DTD (i.e., "table," "list," "prodnote," "annotation," and "note").

7.4.2 Automatic Invocation of Special Navigation Modes

(This section is normative.)

DTB player developers may choose to automatically invoke special player navigation modes when the reader enters a table or list. (See "Document Navigation Features List [Navigation Features]." To support this functionality, a class attribute must be included on the seq or par containing a table or list, using element names drawn from the DTBook DTD (that is, "table" and "list.") DTBs and players may also support this functionality for other structures using the same mechanism.

7.4.3 "Skippable" Structures

(This section is normative.)

Players should offer the user the option to "turn off" certain structures in a DTB, that is, select structures such as notes or line numbers that the player will then automatically skip over during sequential playback. To support this capability, compliant DTBs must include customTest attributes on seqs or pars containing those structures. In addition, customAttributes, as well as a customTest element for each "skippable" structure, must be present in the head of each SMIL file and contain content. At a minimum, customTest attributes must be applied to time containers for linenum, note, noteref, annotation, pagenum, optional prodnote, and sidebar. Attribute values (for customTest attributes on seqs or pars and for the id attribute on customTest elements) shall be the names of the "skippable" elements, drawn from the DTBook DTD (e.g., "linenum", "note", etc.) except as noted in the following paragraph.

Different customTest attributes may be applied to a single DTBook element, depending on the element's attributes. For example, <prodnote render="optional"> might be assigned the customTest "prodnote_opt", while <prodnote render="required"> would not need to be assigned a customTest as the user should not have the option of turning them off.

In DTB applications, the element customTest will only be used when the producer wishes to allow the reader to turn a class of structures on or off, so the override attribute on the customTest element must always be set to "visible." See description of <customTest> above. The SMIL specification chose to make "hidden" the default value, so it is critical that the override="visible" attribute always be present when the customTest element is used.

When a user navigates to a skippable element that has been turned off, the player must render the content of that element.

Section 8.5, "How the NCX Works," describes how information on skippable structures can be gathered in the NCX for efficient presentation to the user.

7.4.4 Packaging Files across Several Media Units

(This section is normative.)

When a DTB spans several media units (e.g., CD-ROM discs), all files required to render any given SMIL file must be present on the same media unit as that SMIL file. This requirement ensures that players need only track the location of SMIL files in order to provide a complete DTB presentation.

7.4.5 Links

(This section is normative.)

If links (i.e., <a> tags with href attributes) are present in the textual content file of a DTB, they must also be included in the corresponding SMIL file(s). Related links in textual content and SMIL files must point to the same information in the textual content and audio files, when audio is present. The default behavior of a link is to be active for at least the duration of the media object it contains. Players may establish other behaviors (e.g., maintaining links in the active state for a preset period of time (possibly modifiable by the user) or until the next link is encountered).

7.4.6 Layout Syntax

(This section is normative.)

This standard allows only SMIL 2.0 Basic Layout syntax (i.e., CSS2 syntax and others are not permitted).

7.4.7 Content of <par>s

(This section is normative.)

Each par can contain no more than one each of text, audio, image and seq. See section 7.4.11, "Text-Only DTBs" for further discussion of this issue.

When both textual content and audio files are present, text and audio objects within the same par must both represent the same body of material (e.g., the same paragraph).

Because of resource limitations on portable DTB players, SMIL presentations should not be created such that multiple audio media objects are rendered simultaneously. Reading systems are not required to support simultaneous rendering of multiple audio files.

7.4.8 Playback of Audio Clips

(This section is normative.)

If the clipBegin attribute is not present in an instance of the <audio> element, the audio file referenced must be played from its beginning. If the clipEnd attribute is not present, the audio file must be played to its end. If the value of the clipEnd attribute exceeds the duration of the audio file, the value must be ignored, and the audio file played to its end.

7.4.9 Notes and Annotations in SMIL

(This section is normative.)

It is strongly recommended that links (<a> tags) be applied to media objects (normally audio) for all noterefs and annorefs, with the corresponding notes and annotations as the targets. The presence of the links will enable key player functionality, such as easy access to notes when noterefs are turned on and notes turned off.

It is recommended that noterefs and notes be implemented in SMIL such that the default, linear presentation (on a simple player) of the noterefs and notes is in the order and location appropriate to the producing agency's policy for rendering note references and notes.

7.4.10 Images in SMIL

(This section is informative.)

Duration of image display will be equal to that of the longest media object or time container contained within the same par. Example 7.2 below shows a sample implementation of SMIL for an image and its associated caption and producer's note.

7.4.11 Text-Only DTBs

(This section is normative.)

Text-only DTBs must include SMIL files. This will ensure user access to the many features enabled by SMIL. As mentioned above, it is strongly recommended that the SMIL file(s) have a level of granularity matching that of the textual content file.

In a DTB which contains no audio material, the duration of text media objects is controlled either by the user (i.e., the player renders the next text object on command) or the player (e.g., a text-to-speech engine or a pacing algorithm for a large-print or Braille display triggers the next media object).

7.5 SMIL Metadata

(This section is normative.)

Metadata is included in the <head> element using the <meta> tag. Content producers may introduce other metadata besides those listed below, if needed. However, additional metadata names must include the prefix "prod:". Players must not fail when encountering unknown metadata but must, at a minimum, ignore it.

7.6 Examples

(This section is informative.)

The following example illustrates the use of head and its contents. The meta element contains the unique id of the DTB as well as the tool that generated this SMIL file and the elapsed time to the start of the file. The visual display location of any text elements with region ="text" or region="notes" is specified by the region elements within layout. The text region occupies most of the screen (the bottom edge of the "text" region is 15% from the bottom of the overall rendering window), while the notes regions occupies only the bottom 15%. The customAttributes indicate that any time containers with customTest="pagenum" will be skipped by default, while time containers with customTest="notes" will automatically be played. If the user interface of the playback device supports it, the user may change these settings.

Example 7.1:


<?xml version="1.0"  encoding="UTF-8"?> <!DOCTYPE smil SYSTEM "dtbsmil100.dtd">
<smil version="1.0.0">
       
    <head>
            <meta name="dtb:uid" content="dk-dbb-4z0065" />
        	<meta name="dtb:generator" content="smilgen2.4" />
        	<meta  name="dtb:totalElapsedTime" content="01:33:56.233" />
     	    <layout>
                   <region  id="text" top="0%" left="0%" right="0%" bottom="15%"/>
                   <region id="notes" top="85%" left="0%" right="0%" bottom="0%"/>
            </layout>
            <customAttributes>
                   <customTest id="pagenum" defaultState="false" override="visible"/>
                   <customTest id="note" defaultState="true" override="visible"/>
            </customAttributes>
    </head>
    <body>
     ...
    </body>

</smil>

Example 7.2 shows the use of SMIL elements within body. The initial seq includes the attribute "dur" which specifies that the entire SMIL file is one hour, three minutes, 24.9 seconds long. Each par (a page number, a heading, two paragraphs, and a figure are shown) includes the segment of text, the image (if applicable), and the corresponding audio clip that are to be rendered simultaneously. The figure falls between the two paragraphs.

The image file is presented in parallel with text and audio versions of the figure caption and a producer's note describing the figure. The entire group is wrapped in a par, with the image file rendered contemporaneously with a sequence of two pars.

The par for the second paragraph includes a link that "wraps" the audio element.

Example 7.2:

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE smil SYSTEM "dtbsmil100.dtd"> 
<smil version="1.0.0"> 

<head>
...
</head> 
<body>
	<seq id="baseseq" dur="1:03:24.9">
		<par id="p1" customTest="pagenum">
		   <text region="text" src="rs.xml#pg_1" />
		   <audio src="rs_fwdx.mp3" clipBegin="00:00:00" clipEnd="00:00:00.91" />
		</par>

		<par id="h1">
		   <text region="text" src="rs.xml#h1_1" />
		   <audio src="rs_fwdx.mp3" clipBegin="00:00:01.62" clipEnd="00:00:02.53" />
		</par>

		<par id="para1">
		   <text region="text" src="rs.xml#para_1" />
		   <audio src="rs_fwdx.mp3" clipBegin="00:00:03.51" clipEnd="00:01:45.36" />
		</par>

		<par id="img1">
		   <img region="image" src="fig1.png" />
		   <seq id="icap1"> 
		      <par id="cap1"> 
		         <text region="caption" src="rs.xml#caption_1" /> 
		         <audio src="rs_fwdx.mp3" clipBegin="00:01:45.98" clipEnd="00:01:52.66" /> 
		      </par>

		      <par id="pnote1" customTest="prodnote">
		         <text region="text" src="rs.xml#prodnote_1" />
		         <audio src="rs_fwdx.mp3" clipBegin="00:01:53.08" clipEnd="00:02:55.34" /> 
		      </par> 
		   </seq>
		</par>

		<par id="para2"> 
		   <text region="text" src="rs.xml#para_2" /> 
		   <a href="rs12.smil#h2_9"><audio src="rs_fwdx.mp3" clipBegin="00:02:56.21" clipEnd="00:04:03.75" /></a>
		</par>
	...
	</seq>
</body>
</smil>

Notes or sidebars containing multiple paragraphs will need to be represented as a series of pars wrapped in a seq, so that a customTest can be applied to the seq, permitting the user to skip the entire sequence. The first part of Example 7.3 illustrates this situation. In addition, note references occurring in the middle of a paragraph will require this special syntax so that the playback device can properly render the content with or without either the note reference or the note.

In the second half of Example 7.3, the first par contains the portion of paragraph 120 preceding the note reference (identified with a span tag in the textual content file as described in section 4.2.1). The second par holds the note reference itself (e.g., "footnote 1"). The third par contains the contents of footnote 1 and the last holds the remainder of paragraph 120. Note that the seq and each par contain a unique id. The region attribute on text will control whether each segment is displayed in the text or notes region.

Example 7.3:

... 
<body> 

	<seq id="baseseq" dur="02:14:34.156"> 
		... (a series of pars)
		<seq id="sidebar_1" customTest="sidebar"> 
			<par id="para_9"> 
				<text region="text" src="rs.xml#para_9" /> 
				<audio src="rs_fwdx.mp3" clipBegin="02:02.711" clipEnd="02:14.678" /> 
			</par>

			<par id="para_10">
				<text region="text" src="rs.xml#para_10" /> 
				<audio src="rs_fwdx.mp3" clipBegin="02:15.545" clipEnd="02:44.612" /> 
			</par> 
		</seq>
		... (a series of pars) 
		<seq id="para_120"> 
			<par id="span_3"> <text region="text" src="rs.xml#span_3" /> 
				<audio src="rs_fwdx.mp3" clipBegin="46:58.744" clipEnd="47:21.659" /> 
			</par> 

			<par id="nref_1" customTest="noteref"> <text region="text" src="rs.xml#nref_1" />
				<audio src="rs_fwdx.mp3" clipBegin="47:22.610" clipEnd="47:23.555" /> 
			</par>

			<par id="ftn_1" customTest="note" class="note"> 
				<text region="notes" src="rs.xml#ftn_1" /> 
				<audio src="rs_notes.mp3" clipBegin="00:00.091" clipEnd="00:34.754" /> 
			</par> 

			<par id="span_4"> 
				<text region="text" src="rs.xml#span_4" /> 
				<audio src="rs_fwdx.mp3" clipBegin="47:24.057" clipEnd="47:582" /> 
			</par>
		</seq> 
		... (a   series of pars)

	</seq>

</body>
... 

7.7 Clock Values

(This section is normative.)

The SMIL 2.0 Timing and Synchronization Module describes several different formats in which "clock values" (timing) may be represented. See Clock Values [SMILclock] in that module. Playback devices must support all of these formats. The three formats are:

Full-clock-val (hours, minutes, seconds, and fractions of seconds): 3:22:55.91

Partial-clock-val (minutes, seconds, and fractions of seconds): 43:15.044

Timecount-val (one or more digits, plus an optional fraction and unit of measurement -- h=hours, min=minutes, s=seconds, ms=milliseconds): 34.6s or 356ms or 58.2. (For Timecount values, if no unit is shown, the default is "s" (for seconds).)

If either of the first two formats is used, leading zeroes must be added to single-digit values for minutes and seconds to ensure mm:ss format.

Contents

8. Navigation Control File (NCX)

8.1 Introduction

(This section is informative.)

The Navigation Control file for XML applications (NCX) exposes the hierarchical structure of a DTB to allow the user to navigate through it. The NCX is similar to a table of contents in that it enables the reader to jump directly to any of the major structural elements of the document, i.e. part, chapter, or section, but it will often contain more elements of the document than the publisher chooses to include in the original print table of contents. It can be visualized as a collapsible tree familiar to PC users. Its development was motivated by the need to provide quick access to the main structural elements of the document without the need to parse the entire marked-up text file, which in many cases may not be present at all. Other elements such as pages, footnotes, figures, tables, etc. can be included in separate, nonhierarchical lists and may be accessed by the user as well.

It is important to emphasize that these navigation features are intended as a convenience for users who want them, and not a burden to those who do not. The alternative of a simple linear playback of the book will be available for those users not requiring the navigation features of the NCX.

8.2 Key NCX Requirements

(This section is normative.)

Every DTB must contain exactly one NCX file. The NCX file must be a valid XML document conforming to ncx100.dtd (see Appendix 3, "NCX DTD") and comply with the additional normative requirements of section 8.4. The version attribute on the ncx element of the NCX file must be explicitly given with the value drawn from the above-named DTD. The NCX file itself must be named with the extension ".ncx".

8.3 NCX Elements

(This section is informative.)

Brief descriptions of the NCX elements follow. Each includes the element declaration extracted from the NCX DTD, along with descriptions of any applicable attributes.

8.4 Other File Requirements

This section collects other normative requirements for the NCX file that cannot be enforced by the DTD.

8.4.1 Navigation Metadata

(This section is normative.)

Metadata shall be included in the head element of the NCX using the meta tag. Content producers may introduce other metadata besides those listed below, if needed; such additional metadata must be prefixed by "prod:". Players must not fail when encountering unknown metadata but must, at a minimum, ignore it.

8.4.2 DTBs Spanning Multiple Media Units

(This section is normative.)

When a DTB spans several distribution media (e.g., multiple CD-ROMs), the full NCX, along with all audio clips referenced by it, must be included on every media unit. This will ensure that the entire NCX will function properly on each piece of media.

8.4.3 mapRef Attribute

(This section is normative.)

The mapRef attribute on each navTarget must reference the innermost navPoint that contains the element referenced by the navTarget.

8.4.4 smilCustomTest Element

(This section is normative.)

Each unique customTest element that appears in one or more SMIL files must have its attributes duplicated in a smilCustomTest element in the head of the NCX.

8.5 How the NCX Works

(This section is informative.)

Upon opening a DTB, a player will ordinarily use the NCX navMap to define the user's choices for navigation. The navMap contains nested navPoints that represent the major divisions of the document. For example, the structure of the book whose NCX is shown in Section 8.6, Example 8.1 would look like this:

Foreword and Standards are at the same level, in this case the highest level, level 1. The nesting of navPoints allows the user to move directly between these objects without passing through the lower level divisions in between. From Foreword, the user can move to level 2 and step to any of the sections of Foreword. Since there is no level 3 under Foreword, no smaller divisions can be accessed from the NCX. Such smaller divisions may be present, but they can only be reached through local navigation. The division of Standards marked 'a.' is at level 4, and can be reached by stepping through 1 Core Services and 1.1.

The user will also have the option of navigating to items that do not fit easily into the hierarchical structure of a document, e.g. pages, footnotes or sidebars. This function is provided by navLists. Unlike navMap, navLists do not represent the structure of the book by nesting navTargets. In example 8.1, there are two navLists: the first contains three navTargets representing page numbers, and the second contains three navTargets representing notes.

Each navPoint or navTarget provides navigation information about one piece of the document, e.g. a chapter heading, section number, page number, figure, etc. The text element contains the actual heading, page number, etc. for visual or text-to-speech presentation; the audio element uses SMIL 2.0 syntax to point to a clip containing the audio presentation of the same information. One or both should be used to give location feedback to the user. The content element provides a pointer to an ID within a SMIL file that marks the beginning of the referenced portion of the DTB.

The required mapRef attribute of navTarget allows synchronization of navLists with the navMap. mapRef points to the innermost navPoint that contains the page number, note, or other element referenced by the navTarget. Similarly, the pageRef attribute of navPoint points to the navTarget representing the page on which the navPoint begins.

This standard offers producers the ability to gather in the head of the NCX information on all skippable elements from the SMIL file(s) (see section 7.4.3, "'Skippable' Structures"). The smilCustomTest element may be repeated to list all skippable elements and their defaultStates. Playback systems may utilize this information to inform users of their options and current settings for skippable structures.

8.6 Examples

(This example is informative.)

Example 8.1:


<?xml version="1.0"  encoding="UTF-8"?>
<!DOCTYPE ncx PUBLIC "-//NISO//DTD ncx v1.0.0//EN"
   "http://www.loc.gov/nls/z3986/v100/ncx100.dtd"
>
<ncx version="1.0.0">
  <head>
    <smilCustomTest id="pagenum" defaultState="false" override="visible"/>
    <smilCustomTest id="note" defaultState="true" override="visible"/>
    <meta name="dtb:uid" content="us-nls-00001"/>
	<meta name="dtb:depth" content="6"/>
	<meta name="dtb:generator" content="NLSv001"/>
	<meta name="dtb:pageNormal" content="47"/>
	<meta name="dtb:pageSpecial" content="0"/>
	<meta name="dtb:pageFront" content="5"/>
	<meta name="dtb:skippable" content="pagenum"/>
  </head>
  <docTitle>
     <text>Revised Standards and Guidelines of Service for the Library of Congress
Network of Libraries for the Blind and Physically Handicapped 1995</text>
     <audio src="rs_title.mp3" />
  </docTitle>
  <docAuthor>
       <text>Association of Specialized and Cooperative Library Agencies</text>
       <audio src="rs_title.mp3" />
  </docAuthor>

  <navMap>
      <navPoint class="chapter" id="lvl1_3" pageRef="p1">
        <navLabel>
          <text>Foreword</text>
          <audio src="rs_fwdx.mp3" clipBegin="00:01.5" clipEnd="00:02.0" />
        </navLabel>
        <content src="sample.smil#h1_3" />
        <navPoint class="section" id="lvl2_1" pageRef="p1">
          <navLabel>
            <text>History</text>
            <audio src="rs_fwdx.mp3" clipBegin="00:03.4" clipEnd="00:03.9" />
          </navLabel>
          <content src="sample.smil#h2_1" />
        </navPoint>
        <navPoint class="section" id="lvl2_2" pageRef="p2">
          <navLabel>
            <text>Development of Standards</text>
            <audio src="rs_fwdx.mp3" clipBegin="00:56.3" clipEnd="00:57.7" />
          </navLabel>
          <content src="sample.smil#h2_2" />
        </navPoint>
      </navPoint>
      <navPoint class="chapter" id="lvl1_7" pageRef="p16">
        <navLabel>
          <text>Standards</text>
          <audio src="rs_stdx.mp3" clipBegin="00:01.3" clipEnd="00:02.1" />
        </navLabel>
        <content src="sample.smil#h1_7" />
        <navPoint class="section" id="lvl2_11" pageRef="p16">
          <navLabel>
            <text>1 Core Services</text>
            <audio src="rs_stdx.mp3" clipBegin="00:02.9" clipEnd="00:04.9" />
          </navLabel>
          <content src="sample.smil#h2_10" />
          <navPoint class="subsection" id="lvl3_1" pageRef="p16">
            <navLabel>
              <text>1.1</text>
              <audio src="rs_stdx.mp3" clipBegin="00:05.7" clipEnd="00:06.7" />
            </navLabel>
            <content src="sample.smil#h3_1" />
            <navPoint class="sub-subsection" id="lvl4_1" pageRef="p16">
              <navLabel>
                <text>a.</text>
                <audio src="rs_stdx.mp3" clipBegin="00:18.7" clipEnd="00:19.1" />
              </navLabel>
              <content src="sample.smil#h4_1" />
            </navPoint>
          </navPoint>
          <navPoint class="subsection" id="lvl3_2" pageRef="p16">
            <navLabel>
              <text>1.2</text>
              <audio src="rs_stdx.mp3" clipBegin="00:50.5" clipEnd="00:51.4" />
            </navLabel>
            <content src="sample.smil#h3_2" />
          </navPoint>
        </navPoint>
      </navPoint>
  </navMap>

  <navList id="pages" class="pagenum">
    <navLabel>
        <text>Pages</text>
    </navLabel>
    <navTarget class="pagenum" id="p1" value="1" mapRef="lvl1_3">
      <navLabel>
        <text>1</text>
        <audio src="rs_fwdx.mp3" clipBegin="00:00" clipEnd="00:00.9" />
      </navLabel>
      <content src="sample.smil#p1" />
    </navTarget>
    <navTarget class="pagenum" id="p2" value="2" mapRef="lvl2_2">
      <navLabel>
        <text>2</text>
        <audio src="rs_fwdx.mp3" clipBegin="00:53.9" clipEnd="00:54.6" />
      </navLabel>
      <content src="sample.smil#p2" />
    </navTarget>
    <navTarget class="pagenum" id="p16" value="16" mapRef="lvl1_7">
      <navLabel>
        <text>16</text>
        <audio src="rs_stdx.mp3" clipBegin="00:00.0" clipEnd="00:00.7" />
      </navLabel>
      <content src="sample.smil#p3" />
    </navTarget>
  </navList>

  <navList id="notes" class="note">
    <navLabel>
        <text>Notes</text>
    </navLabel>
    <navTarget class="note" id="nref_1" mapRef="lvl2_2">
      <navLabel>
        <text>1</text>
        <audio src="rs_fwdx.mp3" clipBegin="01:22.6" clipEnd="01:23.5" />
      </navLabel>
      <content src="sample.smil#nref_1" />
    </navTarget>
    <navTarget class="note" id="nref_2" mapRef="lvl2_2">
      <navLabel>
        <text>2</text>
        <audio src="rs_fwdx.mp3" clipBegin="02:00.6" clipEnd="02:01.4" />
      </navLabel>
      <content src="sample.smil#nref_2" />
    </navTarget>
    <navTarget class="note" id="nref_3" mapRef="lvl2_2">
      <navLabel>
        <text>3</text>
        <audio src="rs_fwdx.mp3" clipBegin="03:13.3" clipEnd="03:14.1" />
      </navLabel>
      <content src="sample.smil#nref_3" />
    </navTarget>
  </navList>
</ncx>

Contents

9. Portable Bookmarks and Highlights

9.1 Introduction

(This section is normative.)

This standard establishes a specific XML file format to support bookmark and highlight export and import. A playback system may allow readers to set bookmarks and to highlight passages in a document, label the marked sections with text or audio notes, and export the resulting collection of marks and notes to other compliant playback devices.

This standard does not require that compliant players support all of the functionality described above. In addition, this standard places no constraints on a playback system's internal system for storing or manipulating the information in the bookmark file. However, if a player supports the export of bookmarks and highlights and their associated notes, the player must format the information as a valid XML file conforming to bookmark100.dtd, the DTD for Portable Bookmarks/Highlights found in Appendix 4. Similarly, a player with bookmark/highlight import capabilities must correctly process bookmarks and highlights and associated notes that are formatted in accordance with boomark100.dtd

Export-capable players must be able to set bookmarks and highlight starts and ends at any point in a DTB, whether based on the audio file or the textual content file. That is, players shall not be limited to capturing location information only at element boundaries. Offsets from element boundaries in audio files shall be identified by <timeOffset> in fractional seconds (Seconds = DIGIT+, Fraction = 3DIGIT). Offsets from element boundaries in textual content files shall be identified by <charOffset>, measured in characters, counting from the nearest previous tag with an id; white space is normalized (collapsed to one character) and tags are not counted.

If a playback device supports user-recording of audio notes on bookmarks or highlights that may be exported, the recording may be in any format supported by the standard. When generating the filename for a note, the playback device must generate a filename extension appropriate to the recording format (See section 5, "Audio File Formats.")

Bookmark files (which may include highlights) shall be named, by default, with the value from the bookmark element uid and the extension ".bmk". For example: "se-tpb-14339.bmk". Players may allow users to apply their own filenames to accommodate character limitations in other filesystems and to avoid filename collisions. To accommodate user-supplied names, players with bookmark import capabilities must be able to open bookmark files and read the uid value to match the correct bookmark file with a DTB. In addition, players offering import functionality must, at a minimum, automatically match an imported file with the currently loaded DTB. It is recommended that if more than one bookmark file is present for a given DTB, players allow the user to choose among them.

Players may implement a variety of systems for numbering or otherwise identifying bookmarks or highlighted sections so the user can step through and choose from a group of them. However, when preparing a bookmark file for export, players must sort the bookmarks and highlights into document order and write them in that order.

9.2 Bookmark/Highlight Elements

(This section is informative.)

Brief descriptions of the Bookmark/Highlight elements follow. Each includes the element declaration extracted from the Bookmark DTD found in Appendix 4, along with descriptions of any applicable attributes.

9.3 Examples

(This section is informative.)

In Example 9.1, the reader has set two bookmarks, one in chapter 1, 22 seconds from the start of paragraph 8 and the other in chapter 3, 88 seconds from the start of paragraph 12. The reader has added the text note "Atlanta burns" to the second bookmark. The user has also highlighted a passage in chapter 4 beginning at the start of paragraph 1 and ending 246 seconds after the start of paragraph 6, labeling it with a ten-second audio comment. The reader last stopped reading (as indicated by the <lastmark>) in chapter 5, paragraph 23. The default filename for this bookmark file would be "us-rfbd-JT065.bmk."

Example 9.1:

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE bookmarkSet 
  SYSTEM "bookmark100.dtd"> <bookmarkSet>
  
    <title>
      <text>Gone with the Wind</text>
      <audio src="gwtw_title.mp3" />
    </title>
    <uid>us-rfbd-JT065</uid>
    
    <lastmark>
      <ncxRef>gwtw.ncx#lvl1_5</ncxRef>
      <uri>gwtw_ch5.smil#para023</uri>
      <timeOffset>173</timeOffset>
    </lastmark>
    
    <bookmark>
      <ncxRef>gwtw.ncx#lvl1_1</ncxRef>
      <uri>gwtw_ch1.smil#para008</uri>
      <timeOffset>22</timeOffset>
    </bookmark>
    
    <bookmark>
      <ncxRef>gwtw.ncx#lvl1_3</ncxRef>
      <uri>gwtw_ch3.smil#para012</uri>
      <timeOffset>88</timeOffset>
      <note>
        <text>Atlanta burns.</text>
      </note>
    </bookmark>
    
    <hilite>
      <hiliteStart>
        <ncxRef>gwtw.ncx#lvl1_4</ncxRef>
        <uri>gwtw_ch4.smil#para001</uri>
        <timeOffset>0</timeOffset>
      </hiliteStart>
      <hiliteEnd>
        <ncxRef>gwtw.ncx#lvl1_4</ncxRef> <uri>gwtw_ch4.smil#para006</uri>
        <timeOffset>246</timeOffset>
      </hiliteEnd>
      <note>
        <audio src="us-rfbd-JT065.wav" clipBegin="00:00.00" clipEnd="00:10.00" />
      </note>
   </hilite>
  
  </bookmarkSet>
  

Example 9.2 shows a text-only file in which the reader last stopped reading 130 characters after the start of paragraph 297.

Example 9.2:

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE bookmarkSet SYSTEM "bookmark100.dtd"> 
<bookmarkSet>

    <title>
       <text>Chemistry Today</text>
    </title>
    <uid>uk-rnib-MM499</uid>

    <lastmark>
      <ncxRef>chemtd.ncx#lvl1_3</ncxRef>
      <uri>chemtd.xml#para297</uri>
      <charOffset>130</charOffset>
    </lastmark>

  </bookmarkSet>
  

Contents

10. Resource File

10.1 Introduction

(This section is informative.)

The optional Resource File supplies text segments and pointers to audio clips or images that may assist the reader in using a DTB. These media objects or "resources" provide information missing from a document or present only in a form inaccessible to the reader. Some examples of applications are:

  1. Documents with definite structures, but missing headings, such as books with multilevel structures but no headings on items below the level of sections. The resource file could contain the word "subsection" for presentation to the reader when stepping through the document via the NCX.
  2. Player implementations that present generic labels such as "level 2" when the user changes levels in the NCX. The resource file could present the actual name of items found at that level in that specific context, e.g., "chapter."
  3. "Where Am I?" applications, especially in situations where headings are absent.
  4. Detailed information about the marked-up textual content file; useful when exact knowledge of a document's finest structure is essential. The resource file could provide text or audio clips of all of the element names in the DTBook DTD, alerting the user when crossing the boundaries of paragraphs, list items, table cells, etc.
  5. Information about the types of text structures that the user may choose to "turn off" via the SMIL file (see section 7.4.3, "'Skippable' Structures"). The Resource File could contain text segments or pointers to audio clips of the names of the structures affected; for example, page numbers, notes, or sidebars.

The Resource File, then, can contain three types of information:
1. Resources tailored to a given document, for use primarily during global navigation. As the user navigates via the NCX, the player, when necessary, will look in the Resource File to locate the resource whose type attribute equals "ncx," whose elementRef attribute value is navPoint or navTarget as appropriate, and whose classRef references the class of the current NCX navPoint or navTarget.

2. Generic representations of the names of elements from the DTBook DTD, for use during local navigation. As the reader issues local navigation commands referencing the textual content file, the player will use the name of the current element in the textual content file to locate the resource with that element name in its elementRef attribute. For example, encountering a paragraph (tagged with <p>...</p>) would call the resource with elementRef equal to "p".

In addition, the classRef attribute on resource allows the DTB producer to create resources tailored to elements with specific class names. For example, different resources could be created for <w class="reservedword">...</w> and <w class="variablename">...</w>.

3. Representations of skippable structures listed in the head of the NCX. The player will locate the resource whose type attribute equals "ncx," whose elementRef attribute value is smilCustomTest and whose idRef attribute references the id of the current smilCustomTest element. For example, the smilCustomTest element tagged <smilCustomTest id="prodnote" />) would call the resource with idRef equal to "prodnote".

The text, audio, and image alternatives allow a resource to be presented in a medium appropriate to the playback system's capabilities and the user's preferences. Images are conceived as holding iconic representations of heading types. The lang attribute on the resource element allows alternative representations to be supplied in multiple languages.

Resources would be called only when appropriate; that is, in response to clear user requirements and when needed. For example, a resource with type="ncx" and classRef="chapter" would not be called if a chapter heading with textual and audio content was already present.

(This section is normative.)

If a Resource File is implemented, it must meet the following requirements. The Resource File is a valid XML 1.0 file conforming to the Document Type Definition resource100.dtd. See Appendix 5, "DTD for Resource File." The version attribute on the resources element of any compliant Resource file must be present and contain the value drawn from the above-named DTD. Parsers cannot enforce the presence of this attribute, so other mechanisms must. The resource file shall be named with the extension ".res". Identical copies of the Resource File shall be distributed on each media unit of the DTB.

10.2 Resource Elements

(This section is informative.)

Brief descriptions of the elements follow. Each includes the element declaration extracted from the Resource DTD, along with descriptions of any applicable attributes.

10.3 Resource File Requirements

(This section is normative.)

If a player implementing resource functionality for DTBook elements encounters an element in the textual content file that includes a class attribute, the player must present the associated resource with the corresponding classRef, if one exists. Otherwise, if the appropriate resource without a classRef exists, the player must present it.

10.4 Examples

(This section is informative.)

In Example 10.1, the Resource File contains a resource for the word "chapter" to be presented when encountering navPoints of this class in the NCX. Resources are supplied for four selected DTBook elements; the last of these resources uses the classRef attribute to specify a given class of the element code. Finally, a resource is provided for a smilCustomTest with an id of "prodnote."

Example 10.1:

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE resources PUBLIC "-//NISO//DTD resource v1.0.0//EN" "http://www.loc.gov/nls/z3986/v100/resource100.dtd">
<resources version="1.0.0">

    <resource type="ncx" elementRef="navPoint" classRef="chapter" lang="en"> 
       <text>Chapter</text>
       <audio src="chapter.mp3" /> 
       <img src="chapter.png" /> 
    </resource > 
  
    <resource type="dtbook" elementRef="li" lang="en"> 
       <text>list item</text>
       <audio src="elemres.mp3" clipBegin="00:36" clipEnd="00:38.14" /> 
    </resource> 
  
    <resource type="dtbook" elementRef="p" lang="en"> 
       <text>paragraph</text>
       <audio src="elemres.mp3" clipBegin="00:47.51" clipEnd="00:49.34" /> 
    </resource> 
  
    <resource type="dtbook" elementRef="td" lang="en"> 
      <text>table cell</text>
      <audio src="elemres.mp3" clipBegin="01:22.12" clipEnd="01:24.01" /> 
    </resource> 
  
    <resource type="dtbook" elementRef="code" classRef="javascript" lang="en"> 
      <text>javascript</text>
      <audio src="elemres.mp3" clipBegin="01:45.15" clipEnd="01:47.01" /> 
    </resource> 
  
    <resource type="ncx" elementRef="smilCustomTest" idRef="prodnote" lang="en"> 
      <text>producer's note</text>
      <audio src="elemres.mp3" clipBegin="01:54.17" clipEnd="01:56.44" /> 
    </resource> 
  
...
</resources >
  
  

In Example 10.2, resources are supplied in both English and Danish for a book whose NCX carries English class names on navPoints (e.g., "chapter"). The "lang" attribute on resource controls which will be presented to the reader.

Example 10.2:


  ... 
  
    <resource type="ncx" elementRef="navPoint" classRef="chapter" lang="da"> 
      <text>Kapitel</text> 
      <audio src="kapitel.mp3" clipBegin="00:00" clipEnd="00:02.23" /> 
      <img src="Kapitel.png" /> 
    </resource> 
  
    <resource type="ncx" elementRef="navPoint" classRef="chapter" lang="en"> 
      <text>Chapter</text> 
      <audio src="chapter.mp3" clipBegin="00:00" clipEnd="00:02.01" /> 
      <img src="chapter.png" /> 
    </resource>

...  
 

Contents

11. Packaging Files for Distribution

11.1 Introduction

(This section is informative.)

If DTBs are distributed on a physical medium such as CD-ROM, producers will sometimes put more than one book on a disk and sometimes use more than one disk to hold a single book. When multiple DTBs are included on a single distribution medium ("media unit"), a simple method of storing this information for easy access by the player is needed, to present to the reader a "bookshelf" of books. When a single DTB spans several media, the player needs access to specific information so that it can provide correct instructions to the reader, e.g., "Insert disk 2," when required. The "Distribution Information File" (or "distInfo File") stores the data needed for these purposes.

In the following scenarios, the player would need accurate "distribution information" to respond appropriately:

  1. Trying to reach an NCX target that lies on another disk.
  2. Trying to reach a bookmark or highlight that is on another disk.
  3. Resuming reading on a different disk than last ended on. "Lastmark" will point to another disk.
  4. Following a cross-reference or other link pointing to a target on another disk.
  5. Retracing path back to point of origin after following a link that required inserting a new disk.
  6. Reading notes during normal playback. If the notes are printed at the end of the chapter or book and are recorded separately from the text where they are referenced, they may fall on a different disk from the noterefs.
  7. Reaching the end of a disk of a multidisk book. This might be handled in another way, but could be implemented using the distInfo File.

A distInfo File would normally be created for each type of distribution medium, whereas other DTB files would be unchanged regardless of how a DTB is distributed.

11.2 Distribution Requirements

(This section is normative.)

When distributing one DTB per media unit, the Package File must be placed in the root of the media unit's file system. When distributing multiple DTBs per media unit, the distInfo File alone must be placed in the root of the media unit's file system. These restrictions do not apply when a DTB is contained on a non-removable storage medium such as a hard drive.

The distInfo File is required on all media units for a given DTB when that DTB spans more than one distribution media or when multiple DTBs are contained on one media unit. Otherwise, a distInfo File is optional. There shall be no more than one distInfo File per media unit (e.g., CD-ROM disk).

The distInfo File, if present, must be a valid XML 1.0 file conforming to distinfo100.dtd (see Appendix 6, "Distribution Information DTD"), and shall be named "distInfo.dinf." The version attribute on the distInfo element must be present and contain the value drawn from the above-named DTD. Parsers will not enforce the presence of this attribute, so other mechanisms must.

Distribution on multiple media units has implications for the production of the NCX and SMIL. For the NCX, see section 8.4.2, "DTBs Spanning Multiple Media Units." For SMIL, see section 7.4.4, "Packaging Files across Several Media Units."

Optional changeMsgs may be used to supply customized messages instructing users on how to proceed when another media unit is needed to continue reading. Such changeMsgs enable presentation of messages in either text or audio. If no changeMsg is present when required, the player must render a default audio or text message (e.g., "please insert disk 2").

Values for the attribute media on the element <book> and for the attribute mediaRef on the elements smilRef and changeMsg shall be in the format "x:y", where x is the sequence number of this media unit, and y is the total number of media units in the distribution of this book.

11.3 DistInfo Elements

(This section is informative.)

11.4 Examples

(This section is informative.)

Example 11.1 shows the distInfo File for the first disk of a book that spans three CD-ROMs. The book element identifies the book through the uid attribute, points to the package file via pkgRef and indicates in the media attribute that this disk is the first of three. Players would parse the package file to obtain book metadata, etc. The distMap element contains a smilRef for each SMIL file in the book (there are 10 in this particular case). The file attribute gives the name of each individual SMIL file. The mediaRef attribute indicates which disk that particular SMIL file (and all audio/text/image files referenced by it) resides upon.

Players would refer to this map when a particular SMIL file is targeted for playback; if the file is not present on the current disk, the changeMsg whose mediaRef attribute matches that of the selected smilRef element would be played.

Example 11.1:


<?xml version="1.0"  encoding="UTF-8"?>
<!DOCTYPE distInfo SYSTEM "distInfo100.dtd">

<distInfo version="1.0.0">

	<book uid="us-rfbd-tbfz284" pkgRef="./FZ284.opf" media="1:3">

		<distMap>

			<smilRef file="FZ284_0001d.smil" mediaRef="1:3"/>
			<smilRef file="FZ284_0002d.smil" mediaRef="1:3"/>
			<smilRef file="FZ284_0003d.smil" mediaRef="1:3"/>
			<smilRef file="FZ284_0004d.smil" mediaRef="1:3"/>
			<smilRef file="FZ284_0005d.smil" mediaRef="2:3"/>
			<smilRef file="FZ284_0006d.smil" mediaRef="2:3"/>
			<smilRef file="FZ284_0007d.smil" mediaRef="2:3"/>
			<smilRef file="FZ284_0008d.smil" mediaRef="2:3"/>
			<smilRef file="FZ284_0009d.smil" mediaRef="2:3"/>
			<smilRef file="FZ284_0010d.smil" mediaRef="3:3"/>

		</distMap>
		<changeMsg mediaRef="1:3">
		<text>Insert disc one.</text>
		<audio src="insert1.wav"/>
		</changeMsg>
		<changeMsg mediaRef="2:3">
		<text>Insert disc two.</text>
		<audio src="insert2.wav"/>
		</changeMsg>
		<changeMsg mediaRef="3:3">
		<text>Insert disc three.</text>
		<audio src="insert3.wav"/>
		</changeMsg>


	</book>

</distInfo>

In Example 11.2, a sample distInfo File is presented for a case where two books are included on one CD-ROM. The file contains pointers to two book package files. Both books are complete on this one media unit so the media attribute is omitted. Players would parse the package files to obtain book metadata, etc.

Example 11.2:


<?xml version="1.0"  encoding="UTF-8"?>
<!DOCTYPE distInfo SYSTEM "distInfo100.dtd">
<distInfo version="1.0.0">

    <book uid="us-nls-db00001" pkgRef="./book1/AllAboutDogs.opf" />
    <book uid="us-nls-db98765" pkgRef="./book2/AllAboutCats.opf" />

</distInfo>

Contents

12. Presentation Styles

12.1 Introduction

(This section is informative)

The W3C has defined mechanisms for separating content from presentation called the Cascading Style Sheet [CSS] and Extensible Style Language [XSL]. CSS (for which two levels of functionality are currently defined, (Level 1 [CSS1] and Level 2 [CSS2]) and XSL allow specific formatting rules for mark-up to be defined and stored independent of the actual content. Default rules are normally applied by the specific playback or rendering system. The CSS Cascade provides a defined mechanism in which style rules may also be applied by the content producer as well as by the user. Producer-supplied style sheets are particularly important for complex documents with formatting or presentational requirements that would not be met by a player's or user's default styles.

CSS or XSL files may be provided by the content producer to control visual formatting of textual content when a DTB is played on a system that incorporates a visual display and supports CSS or XSL.

If a refreshable Braille display is connected to a DTB player, a Braille style sheet can control formatting so that the document is more easily navigable.

Audio CSS (ACSS, part of CSS2) and XSL also support the aural equivalent of visual formatting, and allow for audio cues to be associated with textual content mark-up. For example, chapter starts or page breaks may be indicated with a specific audio cue.

Style sheets are optional components of DTBs and DTB distribution systems. DTB producers may choose to supply default style sheets for any of the above three categories.

12.2 Implementing Style Sheets for DTBs

(This section is normative)

Style sheets must not be written in such a way as to prevent users from overriding them. DTBs referencing style sheets must do so using standard W3C mechanisms to link an XML source to its style sheet (see [XML-Style]). All style sheet processing instructions must include the media attribute specifying which medium the style sheet applies to. Acceptable values are: all (for all media), aural (for audio presentations), Braille (for refreshable Braille displays), embossed (for embossed Braille), handheld (for devices with small monochrome screens), print (for visual formatting of printed output), and screen (for color computer screens). For example:
<?xml-stylesheet href="brstyle.css" type="text/css" media="braille"?>

Playback systems that utilize common PC-based browsers should support presentation styles at least to the extent the browser itself does. However, it is strongly recommended that any DTB player incorporating a visual display implement at least CSS1. Portable players will not generally provide full support for style sheets but may implement a subset of CSS or XSL sufficient for DTB use and the media presented on the player. For example, an audio-only player that is aware of the textual content might support only the audio styles described above.

Developers of playback systems may implement user interface features that support local control of style sheets, thereby allowing the user to define styles that supersede default player- or producer-defined styles. It is strongly recommended that players implementing style sheets support user control of presentation styles.

When multiple style sheets are present for the content being rendered, user-defined styles, if present, shall take precedence, followed by producer-defined and player-defined styles, in that order.

Contents

13. Types of DTB

13.1 Types

(This section is informative.)

Digital talking books produced in compliance with this standard fall into six types representing the proportions in which six key files are present. In all six types, the Package File spine defines the linear reading order of the DTB. A DTB which incorporates audio and textual content files for the full contents of the document, as well as a structured navigation control file (NCX) for efficient navigation (type 4 - audioFullText), offers the most features to a reader.

Type 1 -- Full audio only (dtb:multimediaType = audioOnly)
The full contents of the document are present in recorded speech. The DTB contains no structure. The navigation control file (NCX) contains only the title of the book and a pointer to the first SMIL file. The SMIL files contain only <audio> elements in sequence. This Type of DTB will be represented primarily by "legacy" titles transferred from analog to digital form. Direct navigation to points within the DTB is not possible for the reader.
Type 2 -- Full audio with structure (dtb:multimediaType = audioNCX)
The full contents of the document are present in recorded speech. The NCX contains (via SMIL) links to the structural elements of the book and may contain links to features such as page numbers, narrated footnotes, etc. The SMIL files contain only <audio> elements in sequence. The reader can navigate directly only to items included in the NCX.
Type 3 -- Full or partial audio with structure and partial text (dtb:multimediaType = audioPartText)
The full or partial contents of the document are present in recorded speech. The NCX contains (via SMIL) links to the structural elements of the book and may contain links to features such as page numbers, narrated footnotes, etc. In addition, part of the document is present as a textual content file. The segments included in the textual content file might be chosen either because keyword searching, spelling, and direct access to the text would be beneficial in those segments (e.g., glossaries), or because a synthetic speech rendering would be as useful as a human speech version (e.g., indexes). Images may also be included. The reader can navigate directly to items in the NCX and to tagged items in the textual content file. Where text renditions of a segment are present, they are synchronized with the corresponding audio (and any associated images) in the SMIL files; elsewhere, SMIL contains only <audio> elements in sequence.
Type 4 -- Full audio with structure and full text (dtb:multimediaType = audioFullText)
The full contents of the document are present in recorded speech. The NCX contains (via SMIL) links to the structural elements of the book and may contain links to features such as page numbers, narrated footnotes, etc. The full text of the document is present as a textual content file. Images may also be included. Text, audio, and any images are synchronized in the SMIL files. The reader can navigate directly to items in the NCX and to tagged items in the textual content file.
Type 5 -- Full text with structure and partial audio (dtb:multimediaType = textPartAudio)
The full text of the document is present as a textual content file but only part of the document is present as recorded speech. Images may also be included. The NCX contains (via SMIL) links to the structural elements of the book and may contain links to features such as page numbers, narrated footnotes, etc. The reader can navigate directly to items in the NCX and to tagged items in the textual content file. Where audio renditions of a segment are present, they are synchronized with the corresponding text (and any associated images) in the SMIL files; elsewhere, SMIL contains <text> (and any synchronized <image>) elements in sequence. This type includes books such as dictionaries, where the full text is present but the only audio contains human speech recordings of word pronunciations
Type 6 -- Full text with structure but no audio (dtb:multimediaType = textNCX)
The full text of the document is present as a textual content file. The NCX contains (via SMIL) links to the structural elements of the book and may contain links to features such as page numbers. The reader can navigate directly to items in the NCX and to tagged items in the textual content file. Images may be included. The SMIL files contain <text> elements in sequence, synchronized with any images present. There are no audio files.

13.2 Required Files

(This section is normative.)

The following table shows the six types of DTB and whether each of six files is required (R), optional (O), or not applicable (N/A) for each. Note that the Open eBook Package File (OPF), the navigation control file (NCX), and the SMIL file(s) are required for all types, although the latter two may serve merely as pointers to other files in some cases.

DTB Type OPF NCX Audio Text SMIL Image
audioOnly (Full audio only) R R R N/A R N/A
audioNCX (Full audio+structure) R R R O R N/A
audioPartText (Audio+structure+partial text) R R R R R O
audioFullText (Audio+structure+full text) R R R R R O
textPartAudio (Full text+structure+partial audio) R R R R R O
textNCX (Full text+structure, no audio) R R N/A R R O

13.3 Content Rendering

(This section is normative.)

Players must determine how to render content from the types of files present. If only a textual content file is found, a synthetic speech rendering and output to a braille display and/or screen may be presented, according to the user's preferences and the features provided on the playback system. If only an audio file is present, straight audio playback shall be initiated. A player that supports only a subset of the media included in DTBs must, when encountering an unsupported medium, ignore the unsupported files and correctly render those it does support. In addition, if the playback system cannot render the DTB in any way, based on the value of dtb:multimediaType in the package file metadata, it must report this fact to the user. Further, a playback system should inform the user when unable to render in any way specific content it encounters in the DTB.

Contents

14. Digital Rights Management

This section is informative

Protection of intellectual property will continue to be an important issue for national libraries and other agencies serving people with print disabilities. How this responsibility is met in Digital Talking Book distribution programs, however, will vary from country to country due to differences in the legal environment surrounding the distribution of alternative format materials. It will also vary by item, depending on whether the material is under copyright or in the public domain. When applicable, however, it is critical that agencies utilize reasonable administrative and technical measures to protect copyright holders' rights. It is equally important, though, that agencies ensure access to alternative format materials by their target populations. Thus, DTB producers and distributors that implement DRM systems must do so in a manner that does not limit or prevent access to compliant DTBs by eligible users.

Contents

15. Time-Scale Modification

(This section is informative.)

It is strongly recommended that playback systems implement Time-Scale Modification (TSM) to enable user control of playback speed with or without pitch correction. Playback rates continuously variable from one-third to three times normal speed are recommended.

All time offsets in a DTB (e.g., SMIL and NCX clipBegin/clipEnd, bookmark timeOffsets, etc.), are based on normal play speed. In order to maintain synchronization, a player must process time offsets independently of actual playback speed.

Contents

16. Conformance

This section is informative.

This standard defines two kinds of conformance: file conformance and player conformance. Conformant Digital Talking Books and DTB playback systems must meet all of the applicable requirements specified in the normative sections of this standard. Requirements will vary depending on the media included in a DTB and the functions supported by a DTB player. It should be noted that while many aspects of the standard can be enforced through the DTDs included in this standard, others cannot, and must be enforced through other means.

Contents

17. References to Other Specifications/Documents

(This section is informative.)

The following standards, recommendations, and guidelines are referenced by this standard:

ATAG
Authoring Tool Accessibility Guidelines: http://www.w3.org/TR/WAI-AUTOOLS
CSS
Cascading Style Sheets: http://www.w3.org/Style/css
CSS1
Cascading Style Sheets, Level 1: http://www.w3.org/TR/REC-CSS1
CSS2
Cascading Style Sheets, Level 2: http://www.w3.org/TR/REC-CSS2
DAISY
The DAISY Consortium: http://www.daisy.org
Dublin Core
Dublin Core Metadata Initiative: http://www.purl.org/dc/
DC-Type
Dublin Core Type Vocabulary: http://dublincore.org/documents/dcmi-type-vocabulary/
DTBook HTML
HTML version of expanded DTBook: http://www.loc.gov/nls/z3986/v100/dtbookdoc.htm
DTBook Theory
Theory behind the DTBook DTD: http://www.daisy.org/publications/specifications/theory/dtbook/
ISO
International Organization for Standardization home page: http://www.iso.ch/
ISO 3166
ISO 3166 - Codes for the Representation of Names of Countries and their Subdivisions: http://www.din.de/gremien/nas/nabd/iso3166ma/codlstp1/
ISO 8601
W3C Profile of ISO8601 - Representation of Dates and Times: http://www.w3.org/tr/note-datetime.html
ISO 8859-1
ISO 8859-1 - 8-bit single-byte coded graphic character sets -- Part 1: Latin alphabet No. 1 (HTML character set): http://www.iso.ch
ISO/IEC 10646
ISO/IEC 10646 - Universal Multiple-Octet Coded Character Set: http://www.unicode.org
JPEG
JPEG JFIF V1.02: http://www.jpeg.org/public/jfif.pdf
MPEG
Copies of these MPEG standards: can be obtained from the International Organization for Standardization homepage: http://www.iso.ch or from your national standards body. In the United States, this is the American National Standards Institute: http://www.ansi.org
Navigation Features
Document Navigation Features List: http://www.loc.gov/nls/z3986/background/navigation.htm
NS
XML NameSpaces: http://www.w3.org/TR/REC-xml-names
OEBF
the Open eBook Forum Publication Structure, version 1.0.1: http://www.openebook.org
Player Features
Playback Device Features List: http://www.loc.gov/nls/z3986/background/features.htm
RFC 1766
RFC 1766 - Tags for the Identification of Languages: http://www.ietf.org/rfc/rfc1766.txt
RFC 2083
Portable Network Graphics, Version 1: http://www.ietf.org/rfc/rfc2083.txt
RFC 2396
Uniform Resource Identifiers (URI): Generic Syntaxhttp://www.ietf.org/rfc/rfc2396.txt
RIFFWAV
RIFF WAV format information: ftp://ftp.cwi.nl/pub/audio/RIFF-format
SMIL
SMIL 2.0 W3C Recommendation 07 August 2001: http://www.w3.org/TR/2001/REC- smil20-20010807/
SMILclock
Clock Values section of SMIL Timing and Synchronization Module: http://www.w3.org/TR/2001/REC-smil20-20010807/smil- timing.html#Timing-ClockValueSyntax
SMILmedia
SMIL Media Object Module: http://www.w3.org/TR/2001/REC-smil20-20010807/extended-media-object.html
SMILtiming
SMIL Timing and Synchronization Module: http://www.w3.org/TR/2001/REC-smil20-20010807/smil-timing.html
StructGuide
Structure Guidelines: http://www.daisy.org/products/menupps.htm
SVG
Scalable Vector Graphics http://www.w3.org/TR/SVG/
UAAG
User Agent Accessibility Guidelines: http://www.w3.org/TR/UAAG10/
WCAG
Web Content Accessibility Guidelines: http://www.w3.org/TR/WAI-WEBCONTENT
XML
XML Version 1.0: http://www.w3.org/TR/2000/REC-xml-20001006.html
XML-Style
Associating Style Sheets with XML Documents 1.0: http://www.w3.org/TR/xml-stylesheet/
XSL
Extensible Stylesheet Language (XSL) Version 1.0: http://www.w3.org/TR/xsl/
XSLT
XSL Transformations (XSLT) Version 1.0: http://www.w3.org/TR/xslt

Contents

Appendix 1 - DTBook DTD

(This section is normative.)



<!-- DTBook DTD V1.0.0 2001-09-28 Harvey Bingham -->
<!-- file: dtbook100.dtd -->
<!--dtbook XML Document Type Definition Implementing the
        NISO Digital Talking Book V1.0.0

    Harvey Bingham <hbingham@acm.org>
    George Kerscher <kerscher@montana.com>
    Michael Moodie <mmoo@loc.gov>
    David Pawson <dpawson@rnib.org.uk>

    Assisted by DAISY Consortium and NISO DTB Committee work teams.

 
    1. Purpose

    The Digital Talking Book Document Type Definition (DTD) provides
    the means to mark up the text of a published book to permit support for
    the combination of professional narration and navigation into that
    narration. The markup tags in the book convey its content in structure,
    and contain some metadata about the book content and its structure.

    The Document Type Definition (DTD) names and defines the allowable element
    types, their allowable content, and their attributes. Correct markup
    of the text of the book permits the textual material to be synchronized
    using SMIL files with the professionally narrated version of that book.
    The synchronization can permit concurrent display of the text being
    narrated. The textual content can be searched in context to locate material
    desired for narration.

    More detailed documentation of this dtbook dtd [DTBOOKDTD] is available
    as an html document. See [DTBOOKDOC].

    1.1. Prior Related Work

    The DAISY (Digital Audio-based Information SYstem) Consortium
    contributed substantially to the development of this DTD.
    This application of XML is the next generation after several DAISY
    versions of 2.X specifications, see [DAISY202]. Its Navigation Control
    Center (NCC) provided for synchronizing document structure with
    narration.

    The NCC evolved into an XML application called the "Navigation Control
    File for XML applications" (NCX). Its content is derived from
    the markup of documents tagged using the dtbook DTD. Richer
    structuring capability is one of the objectives of that DTD. The
    Synchronized Multimedia Integration Language [SMIL 2.0] is used
    to provide synchronized narrations and text. The NCX provides
    navigation using the identified elements of documents tagged to this DTD.

    The dtbook DTD includes many, but not all, of the element types found
    in both the [HTML401STRICT] and [XHTML11STRICT] strict DTDs. HTML
    authoring tools permit those additional element tags, and may ignore
    the additional tags that are dtbook-specific.

    1.2. Evolution from HTML

    Dtbook100 has 79 element types. It shares 47 element types with the
    HTML4.0 Strict DTD [HTML401STRICT] (and the XHTML Strict DTD
    [XHTML11STRICT]), omit 30 element types from them, and has 32 unique
    element types.

    Endtag markup is sometimes optional in HTML. It is required for use with
    xhtml and dtbook. Any XML application [XML12] requires endtags, or their
    abbreviated form for empty elements, such as "<br />". The benefit of
    including endtags is that the tagged document has dependable structure
    that can be validated against the dtbook dtd.

    Some tools available for browsing HTML may be used with dtbook
    material, at the expense of their discarding or ignoring some specific
    tagging and attributes that are not part of HTML 4.0. A CSS-based
    stylesheet [CSS1] or [CSS2] that identifies the presentation expectations
    for the HTML and non-HTML tags, or a filter to map those tags onto
    suitable HTML tags can provide appropriate visual presentation.

    2. Document Tagging Content

    A Digital Talking Book document is an XML application. Therefore it
    must begin with the XML processing instruction, followed by the DOCTYPE.

    2.1. XML Processing Instruction

    The XML Processing Instruction identifies the version of XML, and the
    optional character set encoding:

        <?xml version="1.0" encoding="UTF-8" ?>

    Some alternative encodings to "UTF-8" are "UTF-16", "ISO-10646-UCS-2",
    or "ISO-10646-UCS-4" that could be used for the various encodings and
    transformations of Unicode/ISO/IEC 10646. All XML applications are
    expected to support Unicode. Other alternatives are also acceptable,
    including "ISO-8859-1", "ISO-8859-2", ... "ISO-8859-9" for parts of
    ISO 8859. See [ISO8859]. Also the values "ISO-2022-JP", "Shift_JIS",
    or "EUC-JP" can be used for the various Japanese encoded forms of
    JIS X-0208-1997.

    2.2. DOCTYPE Declaration

    The document type declaration, the DOCTYPE, follows. It has several forms.
    The simpler form assumes that the proper version of the dtbook DTD
    is in the same directory as the dtbook file itself.

        <!DOCTYPE dtbook SYSTEM
            "dtbook100.dtd">

    A more general form provides the PUBLIC URI from which the SYSTEM
    filename can be substituted, should that system copy be missing:

        <!DOCTYPE dtbook PUBLIC
            "http://www.loc.gov/nls/z3986/v100/dtbook100.dtd"
            "dtbook100.dtd">

    That assumes the URI can be reached, which may not be true for 
    portable dtbook players. 

    The still more general form recommended for xml applications [XML12] is:

        <!DOCTYPE dtbook PUBLIC
             "-//NISO//DTD dtbook v1.0.0//EN"
             "dtbook100.dtd">

    where the Formal Public Identifier (FPI) on the second line is converted
    to the URI where it may be publicly found:

        http://www.loc.gov/nls/z3986/v100/dtbook100.dtd

    using the [OASIS-TR9401] Entity Management Catalog to resolve that
    indirect mapping from FPI to the dtd.

    That catalog is more generally useful to provide the mapping from
    any external entity names (such as modules) to URIs where they may
    be found. 

    Note that the reference above is to a particular version of the DTD.
    distinguished by the "V100" from subsequent versions.

    2.3 Digital Talking Book File MIME Type

    A Digital Talking Book document is tagged to the dtbook XML 
    application. It's MIME media-type is "text/xml". The tagged book 
    filename should have suffix ".xml". See [RFC2045].

    3. Modular Extension to the DTD

    The dtbook DTD has two parameter entities defined that provide means
    to allow an individual book to modularly extend the content models
    for its block and inline parameter entities

        <!ENTITY % externalblock "">
        <!ENTITY % externalinline "">

    These parameter entities appear in corresponding block and inline
    content models. With this "" content they have no effect on books
    tagged to the dtbook DTD. In a book that needs a modular extension,
    values are given by redefinition in the internal subset of that book.
    This extends the dtbook DTD without having to change it.

    A book can augment the dtbook DTD by including other declarations
    or parameter entity references in the internal subset of declarations
    (in square brackets following the ExternalID and before the concluding
    ">") of the initial DOCTYPE declaration that identifies the dtbook DTD.
    Those additional markup declarations in the internal subset
    take preference over any in the dtbook DTD. The effective DTD is
    thereby augmented by the parameter entity values and any other
    declarations of the book's internal subset.

    For example:

        <!DOCTYPE dtbook SYSTEM
        "dtbook.dtd"
        [
            <!ENTITY dramaModule SYSTEM "drama.dtd">
            %dramaModule;
            <!ENTITY % externalblock "| drama">
            <!ENTITY % externalinline "| stagedir">
        ]>

    The "%dramaModule;" invocation causes all declarations made within
    dramaModule to become the initial part of the dtbook DTD. Within the
    book, the empty entity declarations for both % externalblock and for
    % externalinline are replaced by these new definitions. Thus the
    block element drama can appear wherever block elements may occur in
    dtbook. Similarly any actual content needed for %externalinline;
    (" | stagedir" is shown above) can appear in that extension to wherever
    %inline; appears in the DTD.

    More than one module may be needed and included in a book, for example
    both poem and drama can appear in the internal subset of the book.
    For example, the internal subset of the book could contain:

        <!DOCTYPE dtbook SYSTEM
        "dtbook.dtd"
        [
            <!ENTITY poemModule SYSTEM "poem.dtd">
            %poemModule;
            <!ENTITY dramaModule SYSTEM "drama.dtd">
            %dramaModule;
            <!ENTITY % externalblock "| poem | stanza | verse | drama">
            <!ENTITY % externalinline "| stagedir">
        ]>

    Such external modules need to replicate any parameter entity
    definitions that are used therein since their definitions are needed
    before they can be expanded in their references. They cannot depend
    on parameter entities in the SystemLiteral or PubidLiteral that
    provides this dtbook100.dtd.
   	
    Note that arbitrary external modules from other sources may not have
    all the needed attributes. XML allows augmentation of ATTLISTs in the
    internal subset. For each module, some accommodation to its use in
    dtbook may be required. Any parameter entities needed in the
    content from the internal subset must be declared in those modules.
    Parameter entities in the dtbook dtd are not available when the
    internal subset is recognized.

    Also note that element name collisions may be possible, with names
    in those modules and associated content models overriding those in
    dtbook. For modules under control of dtbook design, such collisions
    can be avoided. A more general solution uses namespace prefixes to
    element and attribute names to clearly indicate the module source.

    The fully marked-up document follows, including tags from the external
    modules in the internal subset. Declarations in the internal subset
    or in external entity references (such as %dramaModule;) referenced
    therein take precedence over like-named ones from the external entity
    containing the base DTD (that is, dtbook100.dtd). Thus the declarations
    from the module containing the drama and poem tags are included along
    with the tags in the base DTD (that is dtbook100.dtd) that are not
    duplicated or redefined in the drama module. So if a <p> tag is
    defined in the drama module, its definition overrides that of the <p>
    tag in dtbook. There is an exception: an ATTLIST for elementname
    that adds attributes from the internal subset augments the ATTLIST
    attributes with different attribute names in the ATTLIST of the same
    elementname in the dtbook100.dtd.

    Note that tools and players processing any extended markup that affects
    navigation structure will need to know of those modular extensions.

    The form above for augmenting the dtbook dtd through the document's
    internal subset does not require the XML namespace mechanism, with
    its namespace-specific prefix on element and attribute names to
    disambiguate any potential name collisions. Use of namespaces
    is not precluded.

    4. References

    [CSS1] Cascading Style Sheets, Level 1

        http://www.w3.org/TR/REC-CSS1

    [CSS2] Cascading Style Sheets, Level 2

        http://www.w3.org/TR/REC-CSS2

    [DAISY202] The DAISY 2.02 Specification for the DAISY Digital Talking
    Book (DTB) format is the predecessor of this dtbook.

        http://www.daisy.org/dtbook/spec/2/final/d202/daisy_202.html

    [DTBOOKDTD] The dtbook DTD v1.0.0 is available at

        http://www.loc.gov/nls/z3986/v100/dtbook100.dtd

    Note that some browsers may prevent downloading a file with suffix dtd.

    [DTBOOKDOC] Expanded DTD documentation of this DTD is available as an
    HTML 4.0 document:

        http://www.loc.gov/nls/z3986/v100/dtbook100doc.htm

    Should revisions occur, a new directory named "vxxx" indicating the
    revision level will contain the revisions. Any prior specific version
    of the dtbook dtd and its documentation will persist.

    [DTBOOK3] The last public beta version was dtbook3-07.dtd.

         http://www.loc.gov/nls/niso/dtbk3-07.dtd
         http://www.loc.gov/nls/niso/dtbk3-07doc.html

    Those and prior versions are available at:

         http://www.loc.gov/nls/z3986/background/

    The history of changes prior to this version, including those
    in internal drafts through dtbk3-10.dtd and before is in:

        http://www.loc.gov/nls/z3986/background/dtbk3-dtd-changes.txt

    In that directory also are the old dtdbk3 dtds and their documentation.
    See its index.html for the list.

        http://www.loc.gov/nls/z3986/background/index.html

    [SMIL 2.0] The Synchronized Multimedia Integration Language SMIL 2.0
    W3C Recommendation 07 August 2001 is available at:

        http://www.w3.org/TR/2001/REC-smil20-20010807/smil20.html

    [HTML401STRICT] "HTML 4.0 Strict DTD", 1999-12-24, Dave Raggett,
    Arnaud Le hors, and Ian Jacobs.  Dtbook100 was originally based on 
    this HTML 4.0 Strict DTD, with design adaptation for dtbook100.
    The description of HTML 4. See [HTML401]. 

        http://www.w3.org/TR/1999/REC-html401-19991224/strict.dtd

    [HTML401] "HTML 4.01 Specification" W3C Recommendation 24 December 1999
    Documentation of the element types that come from that DTD is available at:

        http://www.w3.org/TR/1999/REC-html401-199991224/

    Dtbook100 is now partially harmonized with [XHTML11STRICT] DTD, using
    its camelCase parameter entity names and comments and references
    included following those parameter entities in explanatory comments,
    and extended table content model.

    [ISO10646] "Information Technology - Universal Multiple-Octet Coded
    Character Set (UCS) - Part 1: Architecture and Basic Multilingual
    Plane", ISO/IEC 10646-1:1993. The current specification also takes
    into consideration the first five amendments to ISO/IEC 10646-1:1993.

    [ISO8859] "Information Processing - 8-bit single-byte coded graphic
    character sets - Part 1: Latin alphabet No. 1", ISO 8859-1:1987.
    Other suffixes "-2 through -9" correspond to other character sets
    in the family.

    [OASIS-TR9401] Entity Management, OASIS Technical Resolution 9401:1997
    (Amendment 2 to TR 9401). Paul Grosso, 1997 September 10.

        http://www.oasis-open.org/specs/tr9401.html

    [RFC1556] "Handling of Bi-directional Texts in MIME", H. Nussbacher,
    December 1993.

        http://www.cis.ohio-state.edu/cgi-bin/rfc/rfc1556.html

    [RFC1766] The %ContentType; and %ContentTypes; media types and the
    %Charset; and %Charsets; character encodings are from RFC2045
    "Tags for the Identification of Languages", H. Alvestrand,
    March 1995.

        http://www.cis.ohio-state.edu/cgi-bin/rfc/rfc1766.html

    [RFC2045] "Multipurpose Internet Mail Extensions (MIME) Part One:
    Format of Internet Message Bodies", N. Freed and N. Borenstein,
    November 1996. Note that this RFC obsoletes RFC1521, RFC1522, and RFC1590.

        http://www.cis.ohio-state.edu/cgi-bin/rfc/rfc2045.html

    [RFC2046] "Multipurpose Internet Mail Extensions (MIME) Part Two:
    Media Types", N. Freed, November 1996

        http://www.cis.ohio-state.edu/cgi-bin/rfc/rfc2046.html

    [RFC2396] "Uniform Resource Identifiers (URI): Generic Syntax",
    T. Berners-Lee, R. Fielding, L. Masinter, August 1998. Note that this RFC
    revises and replaces the generic definitions in RFC 1738 and RFC 1808.

        http://www.cis.ohio-state.edu/cgi-bin/rfc/rfc2396.html

    [XHTML11] "XHTML (tm) 1.0: The Extensible HyperText Markup Language",
    W3C Recommendation 26 January 2000, A reformulaton of HTML4 in XML 1.0
    includes case-sensitive names, lower-case for elements and their
    attributes (but not parameter entity names) and in some cases
    equivalent content models that do not require SGML inclusions
    and exclusion exceptions (as occurred in the HTML4.0 strict dtd
    [HTML401STRICT]) is available at:

        http://www.w3.org/TR/xhtml1/

    [XHTML11STRICT] Expanded documentation of the element types that come
    from that XHTML11 strict.dtd and its other DTDs is available within
    the zip file:

        http://www.w3.org/TR/xhtml1/DTD/xhtml1/xhtml1.zip

    [XML12] This dtbook100.dtd is an application of the Extensible Markup
    Language XML 1.0 (Second Edition) W3C Recommendation 6 October 2000.
    It is available at:

         http://www.w3.org/TR/2000/REC-xml-20000106.

    -->

<!--hb: change record:
        1998-10-08 original by Harvey Bingham
        1999-01-23 revision 3-01
        1999-06-25 revision 3-02
        1999-07-20 revision 3-03
        1999-09-16 revision 3-04
        1999-09-24 revision 3-05
        1999-11-05 revision 3-06
        2001-01-31 revision 3-07
        2001-03-08 revision 3-08
        2001-03-30 revision 3-09 basis for dtbook100.dtd
        2001-09-07 revision 3-10 version 1.0.0 first draft
        2001-09-21 revision 3-11 version 1.0.0 second draft
        2001-09-26 revision 3-12 V1.0.0 third draft

    The record of evolution for this dtd may be found in the
    archives. See [DTBOOK3].
    -->

<!-- Comment Classification Conventions

           Some comments start with a pattern followed by a colon:

               Use: element type and its use.
               Ause: attribute use for associated element type.
               hb: Explanation by Harvey Bingham.

           Other comments without such a pattern are dividing lines,
           details about the DTD structure, or about dtbook objects.
    -->

<!--===================== Character Entities =============================-->

<!-- Character entities for interoperability.
        A few characters may have special markup meaning, so are expressed
        as character entities in text, preceded by "&" and followed by ";".
        The notation below, #xHHHH (or #xHH) where H is a hexadecimal-number
        (formed from 1-9 and A-F), indicates the character code position,
        for Unicode/ISO-10646. Note that the "<" and "&" characters in the
        declarations of "lt" and "amp" are doubly escaped to meet the
        requirement that entity replacement be well-formed.
    -->

<!ENTITY lt   "&#x0026;#x003C;"> <!-- "&#38;#60;"  < Less than -->

<!ENTITY gt   "&#x003E;">        <!-- "&#62;"      > Greater than -->

<!ENTITY amp  "&#x0026;#x0026;"> <!-- "&#38;#38;"  & Ampersand -->

<!ENTITY apos "&#x0027;">        <!-- "&#39;"      ' Neutral Quote, Apostrophe-->

<!ENTITY quot "&#x0022;">        <!-- "&#34;"      " Quotation mark -->

<!-- Three larger character sets included in HTML 4.0 are omitted here:
        HTMLlat1.ent, HTMLsymbol.ent, and HTMLspecial.ent.
        Unicode is available to XML applications, so these characters are
        available. The initial processing instruction that identifies
        dtbook as an XML application should use a more inclusive encoding,
        as described at the start of section 2.
    -->

<!--================ Imported Parameter Entity Names =====================-->

<!--Many parameter entities come from the [XHTML11STRICT] strict DTD.-->

<!ENTITY % Character "CDATA">
    <!-- a single character from [ISO10646] -->

<!ENTITY % Charset "CDATA">
    <!-- a character encoding, as per [RFC2045] -->

<!ENTITY % Charsets "CDATA">
    <!-- a space separated list of character encodings, as per [RFC2045] -->

<!ENTITY % ContentType "CDATA">
    <!-- media type, as per [RFC2046] -->

<!ENTITY % ContentTypes "CDATA">
    <!-- comma-separated list of media types, as per [RFC2046] -->

<!ENTITY % Datetime "CDATA">
    <!-- date and time information. ISO date format -->

<!ENTITY % LanguageCode "NMTOKEN">
    <!-- a language code, as per [RFC1766] -->

<!ENTITY % Number "CDATA">
    <!-- one or more digits -->

<!ENTITY % LinkTypes "CDATA">
    <!-- space-separated list of link types -->

<!ENTITY % MediaDesc "CDATA">
    <!-- single or comma-separated list of media descriptors;
        possible values include BRAILLE, PRINT, PROJECTION, SPEECH, ALL,
        or the default SCREEN -->

<!ENTITY % StyleSheet "CDATA">
    <!-- style sheet data -->

<!ENTITY % Text "CDATA">
    <!-- used for titles etc. -->

<!ENTITY % URI "CDATA">
    <!-- a Uniform Resource Identifier, see [RFC2396] -->

<!--================== dtbook External Module Inclusion =================-->

<!ENTITY % externalblock "">
    <!-- placeholder for block element expansion from external modules,
        if changed, string in external subset begins " | blockelementname" -->

<!ENTITY % externalinline "">
    <!-- placeholder for inline element expansion from external modules,
        if changed, string in external subset begins " | inlineelementname" -->

<!--================== dtbook100 Content Models ============================-->

<!ENTITY % list "list">
    <!-- list container for ordered or unordered lists -->

<!ENTITY % dtbookblock
    "author | notice | prodnote | sidebar | note | annotation %externalblock;">
    <!-- block elements unique to dtbook -->

<!ENTITY % inlineinblock
    "a | cite | img | caption | samp | kbd | pagenum">
    <!-- inlines that may alternatively be in block elements -->

<!ENTITY % block
    "p | %list; | dl | div | blockquote | hr | imggroup
     | table | address | line | %dtbookblock;">
    <!-- block elements from html 4.0 augmented by dtbook-unique elements -->

<!--================ Character mnemonic entities =========================-->

<!-- Omitted as XML uses Unicode, so doesn't need them. May need
        character entities if the encoding is more restrictive. -->

<!--=================== Generic Attributes ===============================-->

<!ENTITY % coreattrs
    "id          ID             #IMPLIED
     class       CDATA          #IMPLIED
     style       %StyleSheet;   #IMPLIED
     title       %Text;         #IMPLIED">
    <!-- coreattrs are attributes permissible for most elements
        id       document-wide unique id
        class    space separated list of classes used for rendering
        style    associated style info
        title    advisory title/amplification
    -->

<!ENTITY % i18n
    "lang        %LanguageCode; #IMPLIED
     xml:lang    %LanguageCode; #IMPLIED
     dir         (ltr|rtl)      #IMPLIED">
    <!-- i18n internationalization attributes
        lang        language code (backwards compatible)
        xml:lang    language code (as per XML 1.0 spec)
        dir         direction for weak/neutral text
                    ltr=left to right
                    rtl=right to left
    xhtml recommendation: use both lang and xml:lang, with same value,
    such as "en-US", on the major containing block, to provide source for
    the #IMPLIED values of its descendent elements. See [RFC1556].
    should the values differ, the xml:lang takes precedence.
    See [RFC1556] for handling bi-directional text in MIME.
    -->

<!ENTITY % showin
    "showin (xxx|xxp|xlx|xlp|bxx|bxp|blx|blp) #IMPLIED">
    <!--showin attribute applies for text elements to permit identification
        of the kinds of display appropriate for the element, so presentation
        choice by the reader among alternative readings can be provided, when
        appropriate. Values of showin are coded with three letters in order:
        "b"=Braille, "l"=Largeprint, and "p"=Print; or "x"=inappropriate:

           Value  Braille  Largeprint Print   Interpretation

           "xxx"                              hide
           "xxp"                      p       print only
           "xls"           l                  largeprint only
           "xlp"           l          p       largeprint and print
           "bxx"   b                          braille only
           "bxp"   b                  p       braille and print
           "blx"   b       l                  braille and largeprint
           "blp"   b       l          p       braille, largeprint, and print

        There is no default value, this attribute value is implied
        from the most immediate ancestor that specifies a value.
        If only one showin value is needed it should be included with <book>.

        Different showin content meeting different needs are possible. Both
        largeprint and print are appropriate for screen rendering as well as
        printing. Different corresponding styles may be appropriate.

        It is possible to include equivalent content from any major structure
        below <book> to provide the different content suitable for different
        media. These would be independent, sharing no direct content, possibly
        having common references to images, with different accompanying text
        descriptions.
    -->

<!ENTITY % attrs
    "%coreattrs;
     %i18n;
     smilref      CDATA       #IMPLIED
     %showin;">
    <!-- %attrs; is part of most attribute lists. It includes
    %coreattrs; from which come the four #IMPLIED attributes:
        id, class, style, and title.
    %i18n; from which come the implied attributes: lang, xml:lang, and dir
    smilref is a pointer to a [SMIL 2.0] file, normally to the time container
        (SMIL <par> or <seq>) containing the media object that references this
        element.  However, in a text-only DTB consisting of a sequence of
        text media objects, <smilref> points to the media object that
        references this element. <smilref> allows resumption of SMIL
        presentation at the proper location after navigation via dtbook file.
        All <smilref> values are expected to be added to an augmented
        version of the <dtbook> during production.
    %showin; which value (three letters, from 'x'=ignore, 'b'=braille,
        'l'=largeprint, or 'p'=print) indicates positionally the explicit
        applicability of this element tag to the various media.
    -->

<!ENTITY % attrsrqd
    "id          ID             #REQUIRED
     class       CDATA          #IMPLIED
     style       %StyleSheet;   #IMPLIED
     title       %Text;         #IMPLIED
     smilref     CDATA          #IMPLIED
     %i18n;
     %showin; ">
    <!-- %attrsrqd; includes required id and implied class, style, and
    title.
    %i18n; from which come the implied attributes: lang, xml:lang, and dir
    smilref is a pointer to a [SMIL 2.0] file, normally to the time container
        (SMIL <par> or <seq>) containing the media object that references this
        element.  However, in a text-only DTB consisting of a sequence of
        text media objects, <smilref> points to the media object that
        references this element. <smilref> allows resumption of SMIL
        presentation at the proper location after navigation via dtbook file.
        All <smilref> values are expected to be added to an augmented
        version of the <dtbook> during production.
    %showin; which value (three letters, from 'x'=ignore, 'b'=braille,
        'l'=largeprint, or 'p'=print) indicates positionally the explicit
        applicability of this element tag to the various media.
    -->

<!--================ Document Structure ==================================-->

<!ENTITY % dtbook.content
    "head, book">
    <!-- dtbook.content designates that each dtbook has a <head> of
    metainformation preceding the <book> content.
    -->

<!--Use: dtbook is the root element in the Digital Talking Book DTD.
        <dtbook> contains metadata in <head> and the contents itself in <book>.
    -->

<!ELEMENT dtbook (%dtbook.content;)>

<!--Ause: dtbook The required version attribute contains the specific
        version of the dtd, so that the dtd version for any dtbook can
        be recognized.
        The internationalization (%i18n;) attributes characterize the <book>.
    -->

<!ATTLIST dtbook
  version CDATA #FIXED '1.0.0'
  %i18n;
  >

<!--==================== Book Content ====================================-->

<!--Use: book surrounds the actual content of the document, which
        is divided into <frontmatter>, <bodymatter>, and <rearmatter>.
        <head>, which contains metadata, precedes <book>.
    -->

<!ELEMENT book (frontmatter?, bodymatter?, rearmatter?)>

<!ATTLIST book
  %attrs;
  >

<!--======================= Book Major Structures ========================-->

<!--Use: frontmatter contains preliminary material enclosed in appropriate
        <level> or <level1>. Content may include <doctitle>, <docauthor>
        copyright notice, foreword, acknowledgments, table of contents, etc.
        <frontmatter> serves as a guide to the content and nature of a <book>.
    -->

<!ELEMENT frontmatter (doctitle | docauthor | level | level1 | %block;)+>

<!ATTLIST frontmatter
  %attrs;
  >

<!--Use: bodymatter consists of the text proper of a book, as
        opposed to preliminary material <frontmatter> or supplementary
        information <rearmatter>.
    -->

<!ELEMENT bodymatter (level | level1 | %block;)+>

<!ATTLIST bodymatter
  %attrs;
  >

<!--Use: rearmatter contains supplementary material such as
        appendices, glossaries, bibliographies, and indices. It follows
        the <bodymatter> of the book.
    -->
<!ELEMENT rearmatter (level | level1 | %block;)+>
<!ATTLIST rearmatter
  %attrs;
  >

<!--================== dtbook Recursive Structure level ================-->

<!--Use: level is an alternative tag for marking the major
        structures in a book. It may be used recursively, i.e., repeated
        indefinitely with each successive occurrence nesting within the
        previous. It may also be included in a subsequent higher level.
        Subordinate levels have greater depth. Contrast with the explicit
        <level1>...<level6> elements, which may not be intermixed with
        <level>.
    -->

<!ELEMENT level (levelhd | %block; | %inlineinblock; | level)*>

<!--Ause: level The class attribute identifies the actual name (e.g., part,
        chapter, section, subsection) of the structure it marks.
        The depth attribute indicates the nesting depth, starting at 1.
    -->

<!ATTLIST level
  %attrs;
  depth CDATA #IMPLIED
  >

<!--============ dtbook Hierarchic Structure level1 ... level6 ==========-->

<!--Use: level1 is the highest level container of major divisions of
        a book. Used in <frontmatter>, <bodymatter>, and <rearmatter> to
        mark the largest divisions of the book (usually parts or chapters),
        inside which level2 subdivisions (often sections) may nest.
        The class attribute identifies the actual name (e.g., part, chapter)
        of the structure it marks. Contrast with <level>.
    -->

<!ELEMENT level1 (h1 | level2 | %block; | %inlineinblock;)*>

<!ATTLIST level1
  %attrs;
  >

<!--Use: level2 contains subdivisions that nest within <level1>
        divisions. The class attribute identifies the actual name (e.g.,
        subpart, chapter, subsection) of the structure it marks.
    -->

<!ELEMENT level2 (h2 | level3 | %block; | %inlineinblock;)*>

<!ATTLIST level2
  %attrs;
  >

<!--Use: level3 contains sub-subdivisions that nest within <level2>
        subdivisions (e.g., sub-subsections within subsections). The class
        attribute identifies the actual name (e.g., section, subpart,
        subsubsection) of the subordinate structure it marks.
    -->

<!ELEMENT level3 (h3 | level4 | %block; | %inlineinblock;)*>

<!ATTLIST level3
  %attrs;
  >

<!--Use: level4 contains further subdivisions that nest within <level3>
        subdivisions. The class attribute identifies the actual name
        of the subordinate structure it marks.
    -->

<!ELEMENT level4 (h4 | level5 | %block; | %inlineinblock;)*>

<!ATTLIST level4
  %attrs;
  >

<!--Use: level5 contains further subdivisions that nest within <level4>
        subdivisions. The class attribute identifies the actual name
        of the subordinate structure it marks.
    -->

<!ELEMENT level5 (h5 | level6 | %block; | %inlineinblock;)*>

<!ATTLIST level5
  %attrs;
  >

<!--Use: level6 contains further subdivisions that nest within <level5>
        subdivisions. The class attribute identifies the actual name
        of the subordinate structure it marks.
    -->

<!ELEMENT level6 (h6 | %block; | %inlineinblock;)*>

<!ATTLIST level6
  %attrs;
  >

<!--=================== Text Markup ======================================-->

<!ENTITY % phrase
    "em | strong | dfn | code | samp | kbd | cite | abbr | acronym">
    <!-- inline text elements -->

<!ENTITY % special
    "a | img | br | q | sub | sup | span | bdo | linenum">
    <!-- special inline text elements. -->

<!ENTITY % specialnoa
    "img | br | q | sub | sup | span | bdo | linenum">
    <!-- specialnoa inline text elements for anchor <a>. -->

<!--========================= Inline Entities ============================-->

<!ENTITY % dtbookinline
     "sent | w | pagenum | prodnote | noteref %externalinline;">
    <!-- dtbook added inline text elements -->

<!ENTITY % inline
    "#PCDATA | %phrase; | %special; | %dtbookinline;">
    <!-- inline text elements -->

<!ENTITY % inlinenoa
    "#PCDATA | %phrase; | %specialnoa; %externalinline;">
    <!-- inlinenoa excludes nested <a>. -->

<!ENTITY % inlines
     "#PCDATA | %phrase; | %special; | pagenum | w | prodnote | noteref
     %externalinline;">
    <!-- inlines excludes direct nesting of sentences <sent>. -->

<!ENTITY % inlinew
     "#PCDATA | %phrase; | %special; %externalinline;">
    <!-- inlinew for word <w> excludes any of the %dtbookinline;. -->

<!ENTITY % inlinenopagenum
     "#PCDATA | %phrase; | %special; |
          sent | w | noteref %externalinline;">
    <!-- inlinenopagenum excludes direct <pagenum> in <table> <th> and <td>. -->

<!ENTITY % inlinenoprodnote
     "#PCDATA | %phrase; | %special; |
          sent | w | pagenum | noteref %externalinline;">
    <!-- inlinenoprodnote excludes direct <prodnote>, as they shouldn't nest.-->

<!ENTITY % inlinenoanoprodnote
     "#PCDATA | %phrase; | %specialnoa; |
          sent | w | pagenum | noteref %externalinline;">
    <!-- inlinenoanoprodnote excludes <a> and <prodnote> directly. -->

<!--==================== Flow (Block or Inline) Entities =================-->

<!ENTITY % flow
    "%inlinenoprodnote; | %block;">
    <!-- flow elements add inlinenoprodnote to block -->

<!ENTITY % flownopagenum
    "%inlinenopagenum; | %block;">
    <!-- flownopagenum ideally excludes pagenum though can get in
        through %block; -->

<!--============= Br, Linenum, Address, and Div Content Models ===========-->

<!--Use: br marks a forced line break.
     -->

<!ELEMENT br EMPTY>

<!ATTLIST br
  %coreattrs;
  >

<!--Use: linenum contains a line number in, for example, in legal text.
    -->

<!ELEMENT linenum (#PCDATA)>

<!ATTLIST linenum
  %attrs;
  >

<!--Use: address contains a location at which a person or agency
        may be contacted. By use of <line> to contain content of the
        individual lines, the class attribute can be used to identify
        the content of that <line>. For example, class values might include:
            name, address, region: (state. province, etc.), country, location
            code: (zipcode, provincial code, etc.), phone, fax, email, etc. -->

<!ELEMENT address (%inline; | line)*>

<!ATTLIST address
  %attrs;
  >

<!--Use: div is a generic container for subdivisions of a book. The
        <level1> ... <level6> hierarchy, or the <level> tag used recursively,
        should mark the major hierarchical structures of a book, while <div>
        is used in less formal circumstances or when for production purposes
        it is desired that a structure should be treated differently. The
        class attribute value identifies the actual name (e.g., part, chapter,
        letter) of the structure it marks. Compare with <span> which is
        used in inline settings.
    -->

<!ELEMENT div (%block; | %inlineinblock;)*>

<!--Ause: div The level attribute may extend or augment
        explicit levels, to indicate nesting level, values the positive
        integers, with "1" corresponding to <h1>. 
    -->

<!ATTLIST div
  %attrs;
  level CDATA #IMPLIED
  >

<!--====== dtbook Block Elements Author, Notice, Prodnote, Sidebar ======-->

<!--Use: author identifies the writer of a work other than this one.
        Contrast with <docauthor> which identifies the author of this work.
        <author> typically occurs within <blockquote> or <cite>.
    -->

<!ELEMENT author (%inline;)*>

<!ATTLIST author
  %attrs;
  >

<!--Use: notice contains a warning, caution, or other type of admonition
        normally found in the margin of a book. In contrast with <sidebar>
        a <notice> must be presented at a specific location within the
        text. Its presentation is not optional.
    -->

<!ELEMENT notice (%inline;)*>

<!ATTLIST notice
  %attrs;
  >

<!--Use: prodnote contains language added to the alternative-format
        version by the producer; commonly used to:
        1) provide descriptions of one or more visual elements such
            as charts, graphs, etc.
        2) supply operating instructions
        3) describe differences between the print book and the audio
        version.
    -->

<!ELEMENT prodnote (%flow;)*>

<!--Ause: prodnote The imgref identifies the space-separated id value(s) on
        pertinent images <img>. Rendering of <prodnote> uses the render
        attribute to indicate the content is required or optional for
        the user. If optional, some user preference may allow skipping
        over the content. But <prodnote render="required"> is essential
        content for the user. An audible cue could announce the presence of
        the <prodnote>.
    -->

<!ATTLIST prodnote
  %attrs;
  imgref IDREFS #IMPLIED
  render (required | optional) #IMPLIED
  >

<!--Use: sidebar contains information supplementary to the main
        text and/or narrative flow and is often boxed and printed apart
        from the main text block on a page. It may have a heading <hd>.
    -->

<!ELEMENT sidebar (%flow; | hd)*>

<!ATTLIST sidebar
  %attrs;
  >

<!--Use: note marks a footnote, endnote, etc. Any local reference to
    <note id="yyy"> is by <noteref idref="#yyy">.
    -->

<!ELEMENT note (%block; | %inlineinblock;)+>

<!ATTLIST note
  %attrsrqd;
  >

<!--Use: annotation is a comment on or explanation of a portion of
        a printed book. It differs from <note> in that an <annotation>
        is usually set in the margin or on a facing page, often with
        no explicit reference to it inserted in the text. Any local
        reference to <annotation id="xxx"> is by <annoref idref="#xxx">.
    -->

<!ELEMENT annotation (%block; | %inlineinblock;)+>

<!ATTLIST annotation
  %attrsrqd;
  >

<!--Use: line marks a single logical line of text. Often used in
        conjunction with <linenum> in documents with numbered lines.
    -->

<!ELEMENT line (%inline;)*>

<!ATTLIST line
  %attrs;
  >

<!--================== The Anchor Element ================================-->

<!--Use: a contains an anchor, which is used to reference another location,
        within the same or another <dtbook>.
    -->

<!ELEMENT a (%inlinenoa;)*>

<!--Ause: a The href attribute value may have three forms:
        1) "#idref", in this application, to the element type having the
            referenced id value in this document;
        2) "uri", a uniform resource identifier to a resource, typically a
            document, see [RFC2396], restricted to work with only a <dtbook>
            document;
        3) "uri#xxx". in the resource uri the element with id="xxx".
        Uses of the remaining attributes other than %attrs; are:
            "type" is advisory content MIME type of the target, see [RFC1556];
            "hreflang" is language code of the href target, see [RFC1766];
            "rel" is a list of forward link type(s), the relationship(s)
                expressed by the href value to the target, space-separated
                if multiple;
            "rev" is a list of reverse link types, the relationship(s)
                to this location from the href target, space-separated
                if multiple;
            "accesskey"=accessibility key character shortcut;
            "tabindex"=tabbing order.
    -->

<!ATTLIST a
  %attrs;
  type %ContentType; #IMPLIED
  href %URI; #IMPLIED
  hreflang %LanguageCode; #IMPLIED
  rel %LinkTypes; #IMPLIED
  rev %LinkTypes; #IMPLIED
  accesskey %Character; #IMPLIED
  tabindex %Number; #IMPLIED
  >

<!--========================= Inline Elements ============================-->

<!--Use: em indicates emphasis. Usually <em> is rendered in italics.
    Compare with <strong>.
    -->

<!ELEMENT em (%inline;)*>

<!ATTLIST em
  %attrs;
  >

<!--Use: strong marks stronger emphasis than <em>. Visually <strong> is
     usually rendered bold. -->

<!ELEMENT strong (%inline;)*>

<!ATTLIST strong
  %attrs;
  >

<!--Use: dfn marks the first occurrence of a word or term that is
        defined or explained there or elsewhere in <book>. Often
        <dfn> is rendered in italics, sometimes in parentheses.
    -->

<!ELEMENT dfn (%inline;)*>

<!ATTLIST dfn
  %attrs;
  >

<!--Use: kbd designates information that the reader is to input
        directly into a computer using the keyboard.
    -->

<!ELEMENT kbd (%inline;)*>

<!ATTLIST kbd
  %attrs;
  >

<!--Use: code designates a fragment of computer code.
    -->
<!ELEMENT code (%inline;)*>

<!--Ause: code The attribute xml:space='preserve' preserves whitespace
        therein (except that an XML parser strips leading and trailing
        whitespace before passing the internal content including its
        original whitespace to the application.) The value
        xml:space='default' leaves the whitespace handling to the application.
    -->

<!ATTLIST code
  %attrs;
  xml:space (default | preserve) 'preserve'
  >

<!--Use: samp contains a sample of work created by the author for
        use as an example or template. For example, a sample business letter,
        resume, or computer program output, or form.
    -->

<!ELEMENT samp (%inline;)*>

<!--Ause: samp The xml:space='preserve' preserves whitespace therein (except
        that an XML parser strips leading and trailing whitespace before
        passing the internal content including its original whitespace
        to the application.) The value xml:space='default' leaves the
        whitespace handling to the application.
    -->

<!ATTLIST samp
  %attrs;
  xml:space (default | preserve) 'preserve'
  >

<!--Use: cite marks a reference (or citation) to another document.
    <cite> may occur within an <a href="URL">...</a> should that other
    document be available in the same dtbook distribution.
    -->

<!ELEMENT cite (%inline;)*>

<!ATTLIST cite
  %attrs;
  >

<!--Use: abbr designates an abbreviation, a shortened form of a
        word. For examples: Mr., approx., lbs., rec'd.
    -->

<!ELEMENT abbr (%inline;)*>

<!--Ause: abbr The title attribute value may expand that abbreviation.
    -->

<!ATTLIST abbr
  %attrs;
  >

<!--Use: acronym marks a word formed from key letters (usually
        initials) of a group of words. For examples: UNESCO, NATO, XML.
    -->

<!ELEMENT acronym (%inline;)*>

<!--Ause: acronym The title attribute value may expand that acronym.
        The pronounce attribute value "yes" indicates that the
        acronym is pronounceable as a word (for example, NATO);
        "no" that the acronym is best presented as a sequence
        of letters (for example "US").
    -->

<!ATTLIST acronym
  %attrs;
  pronounce (yes | no) #IMPLIED
  >

<!--Use: sub indicates a subscript character (printed below a
        character's normal baseline). Can be used recursively and/or
        intermixed with <sup>.
    -->

<!ELEMENT sub (%inline;)*>

<!ATTLIST sub
  %attrs;
  >

<!--Use: sup marks a superscript character (printed above a
        character's normal baseline). Can be used recursively and/or
        intermixed with <sub>.
    -->

<!ELEMENT sup (%inline;)*>

<!ATTLIST sup
  %attrs;
  >

<!--Use: span is a generic container for use in inline settings
        when no specific tag exists for a given situation. The class
        attribute may describe the nature of the text it marks (e.g., a
        typographical error). May be used to mark a class of items to which
        styles are to be applied. Compare with <div> which is used in block
        settings. #PCDATA following an inline can be given an id for resumed
        playing by putting it in a <span>.
    -->

<!ELEMENT span (%inline;)*>

<!ATTLIST span
  %attrs;
  >

<!--Use: bdo is used in special cases where the automatic actions
        of the bi-directional algorithm would result in incorrect display.
    -->

<!ELEMENT bdo (%inline;)*>

<!--Ause: bdo The lang attribute indicates the language of the content.
        The dir attribute indicates the writing direction: "ltr" is
        left-to-right, "rtl" is right-to-left.
    -->

<!ATTLIST bdo
  %coreattrs;
  lang %LanguageCode; #IMPLIED
  dir (ltr | rtl) #REQUIRED
  >

<!--==================== dtbook Inline Sentence and Word ================-->

<!--Use: sent marks a sentence.
    -->

<!ELEMENT sent (%inlines;)*>

<!ATTLIST sent
  %attrs;
  >

<!--Use: w marks a word.
    -->

<!ELEMENT w (%inlinew;)*>

<!ATTLIST w
  %attrs;
  >

<!--==== Inline Page Number, Footnote and Annotation Reference =========-->

<!--Use: pagenum contains one page number as it appears from the print
        document, usually inserted at the point within the file immediately
        preceding the first item of content on a new page. 
    -->

<!ELEMENT pagenum (#PCDATA)>

<!--Ause: pagenum The "page" attribute allows three kinds of page numbering
        schemes to be identified:
             "normal" Arabic numbering in the body of the book is
                  the default,
             "front" pages (from the <frontmatter>, often roman numbering),
             "special" pagination schemes such as letter prefix hyphen Arabic
                  number in appendices. Each pagenum needs a unique
        id value, by convention is derived from the actual pagenumber. For
        multi-page continuous content, such as large <img> or <table>, put
        the sequence of <pagenum> on the page where that content starts.
    -->

<!ATTLIST pagenum
  %attrsrqd;
  page (front | normal | special) "normal"
  >

<!--Use: noteref marks one or more characters that reference a footnote
        or endnote <note>. Contrast with <annoref>. Either may be
        independently skippable.
    -->

<!ELEMENT noteref (#PCDATA)>

<!--Ause: noteref idref relates to the note, for example:
        <noteref idref="yyy"> refers to <note id="yyy">. The type attribute
        provides advisory content MIME type of the target, see [RFC1556].
    -->

<!ATTLIST noteref
  %attrs;
  idref CDATA #REQUIRED
  type %ContentType; #IMPLIED
  >

<!--Use: annoref marks a text segment that references an <annotation>.
        Each <annoref> is usually a word, phrase, or whole line that
        is part of the surrounding text (identified in the original
        print book by bolding, italics, etc.). It should not normally
        be allowed to be turned off in a DTB application.
    -->

<!ELEMENT annoref (#PCDATA)>

<!--Ause: annoref The idref attribute refers to the target id of an
        <annotation>. The type attribute provides advisory content MIME
        type of the targeted id, see [RFC1556].
    -->

<!ATTLIST annoref
  %attrs;
  idref CDATA #REQUIRED
  type %ContentType; #IMPLIED
  >

<!--===================== Inline Quotes ==================================-->

<!--Use: q contains a short, inline quotation. Compare with
        <blockquote> which marks a longer quotation set off from the
        surrounding text.
    -->

<!ELEMENT q (%inline;)*>

<!--Ause: q The cite attribute may provide a URI reference.
    -->

<!ATTLIST q
  %attrs;
  cite %URI; #IMPLIED
  >

<!--============================ Images ==================================-->

<!-- Image <img> comes from HTML. An <img> may be grouped
       using <imggroup>, with <caption>, and special
       usage instructions with <prodnote>. The <imggroup>
       element may contain one or more <img> and any associated
       <caption> and <prodnote>. Multiple <img> may share a single
       caption, or multiple <caption> may apply if several captions
       refer to a single <img>. Multiple <prodnote> may apply if different
       versions are needed for different media.
   -->

<!ENTITY % Length "CDATA">
    <!-- measured in pixels. -->

<!ENTITY % MultiLength "CDATA">
    <!-- measured in integer pixels "n", percent "n%" of diplay width, 
        or "0*" indicating minimum appropriate width. Multiple Lengths
        are separated by white-space.
    -->

<!ENTITY % Pixels "CDATA">
    <!-- 0 for no <table> border, positive integer for <table> border width
        in pixels.
    -->

<!--Use: img marks a visual image. An <img> will generally contain a
        longdesc, a pointer to the related <prodnote>. The referencing
        is typically of the form <caption imgref="#yyy">The Caption</caption>
        for the printed caption of the <img id="yyy">.
    -->

<!ELEMENT img EMPTY>

<!--Ause: img The "src" attribute specifies the location of the image file.
        The "alt" attribute may be used to supply a short description of
        the <img>. The attributes height and width provide visual sizing
        information, measured in pixels.
    -->

<!ATTLIST img
  %attrs;
  src %URI; #REQUIRED
  alt %Text; #REQUIRED
  longdesc %URI; #IMPLIED
  height %Length; #IMPLIED
  width %Length; #IMPLIED
  >

<!--Use: imggroup provides a container for <img> or images and associated
        <caption> and <prodnote>. <prodnote> may contain a description
        of the image. The content model allows: 1) multiple <img>
        if they share a caption, with the ids of each <img> in the
        <caption idref="id1 id2 ...">, 2) multiple <caption> if several
        captions refer to a single <img id="xxx"> where  each caption has
        the same <caption idref="xxx">, 3) multiple <prodnote> if
        different versions are needed for different media (e.g.,
        large print, braille, or print.)
    -->

<!ELEMENT imggroup (prodnote | img | caption)+>

<!ATTLIST imggroup
  %attrs;
  >

<!--=================== Horizontal Rule ==================================-->

<!--Use: hr is an empty element indicating a horizontal rule. May be
        used to indicate a break in the text where only blank lines, a row
        of asterisks, a horizontal line, etc. are used in the print book.
    -->

<!ELEMENT hr EMPTY>

<!ATTLIST hr
  %coreattrs;
  >

<!--======================= Paragraphs ===================================-->

<!--Use: p contains a paragraph, which may contain subsidiary <list> or <dl>.
    -->

<!ELEMENT p (%inline; | %list; | dl)*>

<!ATTLIST p
  %attrs;
  >

<!--================ Doctitle, Docauthor and Headings  ===================-->

<!--Use: doctitle marks the title of the book within <frontmatter>.
        By convention it should appear only once, usually first.
        Within <head> is <title> whose contents are generally the same.
    -->

<!ELEMENT doctitle (%inline;)*>

<!ATTLIST doctitle
  %attrs;
  >

<!--Use: docauthor marks each author or editor of this work. Compare with
        <author>, used to mark the author of another work, within <blockquote>
        or <cite>.
    -->

<!ELEMENT docauthor (%inline;)*>

<!ATTLIST docauthor
  %attrs;
  >

<!--Use: levelhd contains the text of a heading within <level>.
        Corresponds to <h1> through <h6> used in <level1> through <level6>.
    -->

<!--Ause: levelhd The depth value is a positive integer, corresponding
        to the <h1>...<h6> levelN, though not limited to just six levels.
        Any depth value, "n", should match that on the enclosing
        <level depth="n">.
    -->

<!ELEMENT levelhd (%inline;)*>

<!ATTLIST levelhd
  %attrs;
  depth CDATA #IMPLIED
  >

<!--Use: h1 contains the text of the heading for a <level1>
        structure.
    -->

<!ELEMENT h1 (%inline;)*>

<!ATTLIST h1
  %attrs;
  >

<!--Use: h2 contains the text of the heading for a <level2>
        structure.
    -->

<!ELEMENT h2 (%inline;)*>

<!ATTLIST h2
  %attrs;
  >

<!--Use: h3 contains the text of the heading for a <level3>
        structure.
    -->

<!ELEMENT h3 (%inline;)*>

<!ATTLIST h3
  %attrs;
  >

<!--Use: h4 contains the text of the heading for a <level4>
        structure.
    -->

<!ELEMENT h4 (%inline;)*>
<!ATTLIST h4
  %attrs;
  >

<!--Use: h5 contains the text of the heading for a <level5>
        structure.
    -->

<!ELEMENT h5 (%inline;)*>

<!ATTLIST h5
  %attrs;
  >

<!--Use: h6 contains the text of the heading for a <level6>
        structure.
    -->

<!ELEMENT h6 (%inline;)*>

<!ATTLIST h6
  %attrs;
  >

<!--Use: hd marks the text of a heading in a <list> or <sidebar>.
    -->

<!ELEMENT hd (%inline;)*>

<!ATTLIST hd
  %attrs;
  >

<!--=================== Preformatted Text ================================-->

<!-- HTML or XHTML preformatted text is omitted, as inappropriate for
        narrated material. -->

<!--=================== Block-like Quotes ================================-->

<!--Use: blockquote indicates a block of quoted content that is set
        off from the surrounding text by paragraph breaks. Compare with
        <q> which marks short, inline quotations.
    -->

<!ELEMENT blockquote (%block;)*>

<!--Ause: blockquote The cite attribute permits inclusion of the
       URI from which the <blockquote> came.
    -->

<!ATTLIST blockquote
  %attrs;
  cite %URI; #IMPLIED
  >

<!--================= Definition List, and Other Lists ====================-->

<!--Use: dl contains a definition list, usually consisting of
        pairs of terms <dt> and definitions <dd>. Any definition can contain
        another definition list.
    -->

<!ELEMENT dl (dt | dd | pagenum)+>

<!ATTLIST dl
  %attrs;
  >

<!--Use: dt marks a term in a definition list.
    -->

<!ELEMENT dt (%inline;)*>

<!ATTLIST dt
  %attrs;
  >

<!--Use: dd marks a definition of a term within a definition list.
    -->

<!ELEMENT dd (%flow;)*>

<!ATTLIST dd
  %attrs;
  >

<!--Use: list contains some form of list, ordered or unordered.
        The list may have intermixed heading <hd> (generally only one,
        possibly with <prodnote>) and an intermixture of list items <li>
	and <pagenum>. If bullets and outline enumerations are part of
        the print content, they are expected to prefix those list items
        in content, rather than be implicitly generated. Note: XHTML
        has explicit list element types: ol for ordered, and ul for unordered.
    -->

<!ELEMENT list (hd | prodnote | li | pagenum)+>

<!--Ause: list The "type" attribute indicates whether the list items
        <li> are ordered "ol" or unordered "ul".
        The depth indicates nesting depth, starting at 1.
        The enum value indicates: 1=integer, a=lowercase, U=uppercase,
        i=lowercase Roman, or X=uppercase Roman.
        The bullet value can come from Unicode, using the entity
        reference form &xdddd;
    -->

<!ATTLIST list
  %attrs;
  type (ol | ul) #IMPLIED
  depth CDATA #IMPLIED
  enum (1 | a | U | i | X) #IMPLIED
  bullet CDATA #IMPLIED
  >

<!--Use: li marks each list item in a <list>. <li> content may be
        either inline or block and may include other nested
        lists. Alternatively it may contain a sequence of list item
        components, <lic>, that identify regularly occurring content,
        such as the heading and page number of each entry in a
        table of contents.
    -->

<!ELEMENT li (%flow; | lic)*>

<!ATTLIST li
  %attrs;
  >

<!--Use: lic ("list item component") allows ordered substructure
        within a list item <li>.  Used when a list item is made up of
        two or more components, as in a table of contents entry.
        The same number of <lic> should occur in each <li>. If not,
        correspondence of <lic> in different <li> is in order of
        occurrence for the current writing direction of the <li>.
    -->

<!ELEMENT lic (%inline;)*>

<!--lic class attribute may be used to identify the particular
        component of a list item <li>. For example, in a table of contents
        class values might include "section", and "pagenumber".
    -->

<!ATTLIST lic
  %attrs;
  >

<!--======================= Tables =======================================-->

<!--hb: the XHTML <table> model is used, including the presentational
        attributes that have little meaning in Digital Talking Books,
        but may be useful for concurrent display in different media.
	Note: The XHTML <table> model has been enhanced from HTML to allow
        a <table> of just rows <tr>.
    -->

<!ENTITY % Scope
    "(row | col | rowgroup | colgroup)">
    <!-- Scope specifies a set of data cells for which the <th> provides
        header information. -->

<!ENTITY % TFrame
    "(void | above | below | hsides | lhs | rhs | vsides | box | border)">
    <!-- TFrame identifies the sides that are visually framed. -->

<!ENTITY % TRules
    "(none | groups | rows | cols | all)">
    <!-- %TRules identifes where visual rulings appear. -->

<!ENTITY % cellhalign
    "align      (left|center|right|justify|char) #IMPLIED
     char       %Character;    #IMPLIED
     charoff    %Length;       #IMPLIED  ">
    <!-- % cellhalign align sets horizontal alignment of content in
         a table cell.  char indicates a character expected in each table
         cell of a column that text should align on, charoff sets the
         alignment offset of the first character to align on, as
         specified with char. cellalign value inheritance if unspecified
         is (high to low) <th>|<td> <col> <tr> <thead>|<tbody>|<tfoot>
         -->

<!ENTITY % cellvalign
    "valign     (top|middle|bottom|baseline) #IMPLIED">
    <!-- % cellvalign valign sets vertical alignment of content in a
         table cell. valign value inheritance if unspecified is
         (high to low) <th>|<td> <col> <colgroup> <thead>|<tbody>|<tfoot>
         -->

<!--Use: table contains cells of tabular data arranged in rows and columns.
        A <table> may have a <caption>. It may have descriptions of
        the columns in <col>s or groupings of several <col> in <colgroup>.
        A simple <table> may be made up of just rows <tr>.
        A long table crossing several pages of the print book should
        have separate <pagenum> values for each of the pages containing
        that <table> indicated on the page where it starts.
        Note the logical order of optional <thead>, optional <tfoot>,
        then one or more of either <tbody> or just rows <tr>. This order
        accommodates simple or large, complex tables. The <thead> and <tfoot>
        information usually helps identify content of the <tbody> rows,
        For a multiple-page print <table> the <thead> and <tfoot> are
        repeated on each page, but not redundantly tagged.
    -->

<!ELEMENT table (caption?, (col* | colgroup*), thead?, tfoot?, (tbody+| tr+))>

<!--Ause: table The summary attribute value provides a textual summary.
        The attributes: width, border, frame, rules, cellspacing, and
        cellpadding provide visual presentation guidance. See their
        explanation in the comment following those parameter entity
        declarations.
    -->

<!ATTLIST table
  %attrs;
  summary %Text; #IMPLIED
  width %Length; #IMPLIED
  border %Pixels; #IMPLIED
  frame %TFrame; #IMPLIED
  rules %TRules; #IMPLIED
  cellspacing %Length; #IMPLIED
  cellpadding %Length; #IMPLIED
  >

<!--Use: caption describes a <table> or <img>. If used with <table> it
        must follow immediately after the <table> start tag. If used
        with <img> or <imggroup> it is not so constrained.
    -->

<!ELEMENT caption (%inline;)*>

<!--Ause: caption The imgref attribute value (or
        space-separated id values) identifies the <img>s to which
        it applies.
    -->

<!ATTLIST caption
  %attrs;
  imgref IDREFS #IMPLIED
  >

<!--Use: thead marks header information in a <table>, consisting of
        one or more rows <tr> of <th> cells. On multiple-page printed
        tables, <thead> rows are repeated at the top of the <table>
        and on top of its continuation on other pages.
    -->

<!ELEMENT thead (tr)+>

<!ATTLIST thead
  %attrs;
  %cellhalign;
  %cellvalign;
  >

<!--Use: tfoot marks footer information in a <table>, consisting of
        one or more rows <tr>, usually of <th> cells. On multiple-page
        printed tables, <tfoot> rows are repeated at the bottom of
        the first page of the <table> and its continuation on other pages.
    -->

<!ELEMENT tfoot (tr)+>

<!ATTLIST tfoot
  %attrs;
  %cellhalign;
  %cellvalign;
  >

<!--Use: tbody marks a group of rows in the main body of a <table>. If the
        <table> is divided into several sections, each consisting of a
        number of rows, each section would be separately tagged with <tbody>.
        The same <thead> and <tfoot> apply to every <tbody> section.
    -->

<!ELEMENT tbody (tr)+>

<!ATTLIST tbody
  %attrs;
  %cellhalign;
  %cellvalign;
  >

<!--Use: colgroup groups adjacent columns <col> that are semantically related.
        The <col> in a <colgroup> may inherit attribute values
        from it, or an enclosing parent, such as <thead>, <tfoot>, or
        <tbody>, or within a <table>.
    -->

<!ELEMENT colgroup (col)*>

<!--Ause: colgroup The span attribute indicates how many columns are
        being spanned, unless overridden by a span attribute value on
        one of those <col>.
        The width may contain a space-separated list of pixel widths for
        each <col>, or percentages if values end in "%",
        or "0*" to indicate minimal acceptable width based on column
        content.
    -->

<!ATTLIST colgroup
  %attrs;
  span NMTOKEN "1"
  width %MultiLength; #IMPLIED
  %cellhalign;
  %cellvalign;
  >

<!--Use: col is a means to apply attribute values to a column of a
        <table>. 
    -->

<!ELEMENT col EMPTY>

<!--Ause: col The span value indicates how many columns the <col>
        extends, in the writing direction of the <table>. The
        attribute values apply to <th> and <td> that start in the
        column, even if they extend into the next column(s), by 
        span value more than 1,  and that next <col> may have differenti
        attribute values. Attribute values from the enclosing row <tr>
        may override those from the <col> as source for implied values
        for <th> and <td> therein.
    -->

<!ATTLIST col
  %attrs;
  span NMTOKEN "1"
  width %MultiLength; #IMPLIED
  %cellhalign;
  %cellvalign;
  >

<!--Use: tr marks one row of a <table> containing <th> or <td> cells.
    The values for %cellhalign; and %cellvalign; provide default
    values for <th> and <td> in the row, overriding any from <col>.
    -->

<!ELEMENT tr (th | td)+>

<!ATTLIST tr
  %attrs;
  %cellhalign;
  %cellvalign;
  >

<!--Use: th indicates a table cell containing header information.
    -->

<!ELEMENT th (%flownopagenum;)*>

<!--Ause: th The uses of attributes other than %attrs;, %cellvalign;
        and %cellhalign; are:

            abbr provides an abbreviated name for a <th> cell
            that can be used when referring to that <th> cell.
            Its default value is the cell content.

            axis usually applied only to <th> cells.
            It gives a short name for that header content,

            headers provides the id value(s), used with <td>
            cells, to reference one or more cells with <th id="xxx">
            that contain headings that collectively describe or qualify the
            content of the cell, for example <td headers="id1 id2">.

            scope value identifies one of 
                (row | rowgroup | column | colgroup)
            to which the header information applies.

            rowspan indicates the total number of rows below 
            that the cell extends, by default 1.

            colspan indicates the total number of columns the
            cell extends, by default 1, in the writing direction
            of the table.
    -->

<!ATTLIST th
  %attrs;
  abbr %Text; #IMPLIED
  axis CDATA #IMPLIED
  headers IDREFS #IMPLIED
  scope %Scope; #IMPLIED
  rowspan NMTOKEN "1"
  colspan NMTOKEN "1"
  %cellhalign;
  %cellvalign;
  >

<!--Use: td indicates a table cell containing data.
    -->

<!ELEMENT td (%flownopagenum;)*>

<!--Ause: td The uses of attributes other than %attrs;, %cellhalign; and
        %cellvalign; are:

            abbr provides an abbreviated name for a <th> cell
            that can be used when referring to that <th> cell.
            Its default value is the cell content.

            axis usually applied only to <th> cells.
            It gives a short name for that header content,

            headers provides the id value(s), used with <td>
            cells, to reference one or more cells with <th id="xxx">
            that contain headings that collectively describe or qualify the
            content of the cell, for example <td headers="id1 id2">.

            scope value identifies one of 
                (row | rowgroup | column | colgroup)
            to which the header information applies.

            rowspan indicates the total number of rows below 
            that the cell extends, by default 1.

            colspan indicates the total number of columns the
            cell extends, by default 1, in the writing direction
            of the table.
    -->

<!ATTLIST td
  %attrs;
  abbr %Text; #IMPLIED
  axis CDATA #IMPLIED
  headers IDREFS #IMPLIED
  scope %Scope; #IMPLIED
  rowspan NMTOKEN "1"
  colspan NMTOKEN "1"
  %cellhalign;
  %cellvalign;
  >

<!--================ Document Head =======================================-->

<!ENTITY % head.misc
    "style | meta | link">

<!--Use: head contains metainformation about the book but no
        actual content of the book itself, which is placed in <book>.
        This information is consonant with the <head> information
        in xhtml, see [XHTML11STRICT]. Other miscellaneous elements can
        occur before and after the required <title>. By convention
        <title> should occur first.
    -->

<!ELEMENT head ((%head.misc;)*,title,(%head.misc;)*)>

<!--Ause: head The profile attribute gives one or more whitespace-separated
        profile URI targets that may provide additional information
        about the current document.
    -->

<!ATTLIST head
  %i18n;
  profile %URI; #IMPLIED
  >

<!--Use: title contains the title of the book but is used only as
        metainformation in <head>. Use <doctitle> within <book> for
        the actual book title, which will usually be the same.
    -->

<!ELEMENT title (#PCDATA)>

<!ATTLIST title
  %i18n;
  >

<!--Use: link is an empty element appearing in the <head> section
        of a document that establishes a connection between the current
        document and another document. The <link> element conveys
        relationship information (for example, "next" and "previous") that
        may be rendered by user agents in a variety of ways.
    -->

<!ELEMENT link EMPTY>

<!--Ause: link Each attribute use indicated by a parameter entity is
        defined in the comment following its definition.
    -->

<!ATTLIST link
  %attrs;
  charset %Charset; #IMPLIED
  href %URI; #IMPLIED
  hreflang %LanguageCode; #IMPLIED
  type %ContentType; #IMPLIED
  rel %LinkTypes; #IMPLIED
  rev %LinkTypes; #IMPLIED
  media %MediaDesc; #IMPLIED
  >

<!--Use: meta indicates metadata about the book. It is an empty
        element that may appear repeatedly only in <head>.
    -->

<!ELEMENT meta EMPTY>

<!--Ause: meta The http-equiv attribute connects the content attribute
        value to an http header field. The name attribute value identifies
        the specific kind of content value. The scheme value indicates
        a predetermined format for interpreting the content value.
    -->

<!ATTLIST meta
  %i18n;
  http-equiv NMTOKEN #IMPLIED
  name NMTOKEN #IMPLIED
  content CDATA #REQUIRED
  scheme CDATA #IMPLIED
  >

<!--Use: style provides the means to include styling information
        that applies to the book. It may appear only in <head>.
        It may include CDATA sections. 
    -->

<!ELEMENT style (#PCDATA)>

<!--Ause: style The type attribute indicates the MIME-Type [RFC2045].
        Type value should be "text/css", rather than "text/javascript". 
        The media attribute value indicates the media for stylesheet
        definition(s); if multiple, separated by commas.
        The title value can provide menu choice among alternative
        stylesheets. The xml:space value indicates that whitespace
        in the <style> content is preserved without need to
        include its value in each <style>.
    -->

<!ATTLIST style
  %i18n;
  type %ContentType; #REQUIRED
  media %MediaDesc; #IMPLIED
  title %Text; #IMPLIED
  xml:space (default | preserve) 'preserve'
  >


Contents

Appendix 2 - DTB-Specific SMIL DTD

(This section is normative.)



<!--SMIL 2.0 DTB-specific DTD Version 1.0.0 2001-09-27
file: dtbsmil100.dtd 

Authors: Michael Moodie, Tom McLaughlin, Lloyd Rasmussen

Description:	
This DTD is intended for use only with DTB applications.  Documents valid to this DTD will also be valid to the DTB SMIL Profile, but not necessarily vice versa, as this DTD contains only a subset of the elements and attributes present in the DTB SMIL Profile.  This DTD is in some areas more restrictive than the Profile (e.g., requiring IDs on some elements), to enforce structure critical to the DTB application.

The following identifiers apply to this DTD: 
"-//NISO//DTD dtbsmil v1.0.0//EN"
"http://www.loc.gov/nls/z3986/v100/dtbsmil100.dtd"
-->


<!ENTITY	% Core.attrib
	"id	ID	#IMPLIED
	class		CDATA		#IMPLIED
	title		CDATA		#IMPLIED"
>

<!ENTITY % URI "CDATA">
    <!-- a Uniform Resource Identifier, see [RFC2396] -->

<!ELEMENT	smil	(head, body) >
<!ATTLIST	smil
	%Core.attrib;
	version		CDATA		#FIXED "1.0.0"
	xml:lang	NMTOKEN		#IMPLIED
>

<!ELEMENT	head	((meta)*, (layout)?, (customAttributes)? ) >
<!ATTLIST	head
	%Core.attrib;
	xml:lang	NMTOKEN		#IMPLIED
>


<!ELEMENT	meta	EMPTY >
<!ATTLIST	meta
	name		CDATA		#REQUIRED
	content		CDATA		#IMPLIED
>

<!-- only smil basic layout allowed; not CSS2. 
     root-layout not included, is implementation dependent.
-->
<!ELEMENT	layout	(region)+ >
<!ATTLIST	layout
	%Core.attrib;
	xml:lang	NMTOKEN		#IMPLIED
>

<!ELEMENT	region	EMPTY >
<!ATTLIST	region
	id				ID		#REQUIRED
	height			CDATA		'auto'
	width			CDATA		'auto'
	bottom			CDATA		'auto'
	top				CDATA		'auto'
	left			CDATA		'auto'
	right			CDATA		'auto'
	fit				(hidden|fill|meet|scroll|slice)	'hidden'
	z-index			CDATA		#IMPLIED
	backgroundColor	CDATA		#IMPLIED
	showBackground	(always|whenActive)	'always'
>

<!ELEMENT	customAttributes	(customTest)+ >
<!ATTLIST	customAttributes
	%Core.attrib;
	xml:lang	NMTOKEN		#IMPLIED
>
	
<!ELEMENT	customTest	EMPTY >
<!ATTLIST	customTest
	id				ID			#REQUIRED
	class			CDATA		#IMPLIED
	defaultState	(true|false) 	'false'
	title			CDATA		#IMPLIED
	xml:lang		NMTOKEN		#IMPLIED
	override		(visible|hidden) 'hidden'
>

<!-- Even though body functions as a seq, and you don't need a base set of seqs wrapping the whole presentation, for DTB applications a base set of seqs should be used.  The dur attribute on the first seq is used by the player to determine the length of the SMIL presentation. -->
<!ELEMENT	body	(par|seq|text|audio|img|a)+ >
<!ATTLIST	body
	%Core.attrib;
	xml:lang	NMTOKEN		#IMPLIED
>

<!ELEMENT	seq	(par|seq|text|audio|img|a)+ >
<!ATTLIST	seq	
	id			ID			#REQUIRED 
	class		CDATA		#IMPLIED
	customTest 	IDREF		#IMPLIED
	dur			CDATA		#IMPLIED

>

<!-- pars are not allowed to nest.
-->
<!ELEMENT	par	(seq|text|audio|img|a)+ >
<!ATTLIST	par
	id		ID		#REQUIRED
	class		CDATA		#IMPLIED
	customTest 	IDREF		#IMPLIED
>

<!ELEMENT	text	EMPTY >
<!ATTLIST	text
	id			ID			#IMPLIED
	region		CDATA		#IMPLIED
	src			CDATA		#REQUIRED
	type		CDATA		#IMPLIED
>
	
<!ELEMENT	audio	EMPTY >
<!ATTLIST	audio
	id			ID			#IMPLIED
	src			CDATA		#REQUIRED
	type		CDATA		#IMPLIED
	clipBegin	CDATA		#IMPLIED
	clipEnd		CDATA		#IMPLIED
	region		CDATA		#IMPLIED
>

<!ELEMENT	img	EMPTY >
<!ATTLIST	img
	id			ID		#IMPLIED
	region		CDATA		#IMPLIED
	src			CDATA		#REQUIRED
	type		CDATA		#IMPLIED
>

<!ELEMENT	a	(text|audio|img)* >
<!ATTLIST	a
	href		%URI;		#REQUIRED
	xml:lang	NMTOKEN		#IMPLIED
	%Core.attrib;
>

Contents

Appendix 3 - NCX DTD

(This section is normative.)


<!-- NCX 1.0.0 DTD  2001-09-27 
file: ncx100.dtd                                 

  Authors: Mark Hakkinen, George Kerscher, Tom McLaughlin, James Pritchett, and Michael Moodie
    
  Description:
                                                  
  NCX (Navigation Control for XML applications) is a generalised navigation definition DTD for application
to Digital Talking Books, eBooks, and general web content models.                                                
This DTD is an XML application that layers navigation functionality on top of SMIL 2.0  content.                                       
  
  The NCX defines a navigation path/model which may be applied upon existing publications,
without modification of the existing publication source, so long as the navigation targets within
the source publication can be directly referenced via a URI.                      
         		
-->
   
<!-- The following identifiers apply to this DTD:
	"-//NISO//DTD ncx v1.0.0//EN"
	"http://www.loc.gov/nls/z3986/v100/ncx100.dtd"
-->

<!-- Basic Entities -->

<!ENTITY % i18n 
  "lang		NMTOKEN		#IMPLIED
  dir		(ltr|rtl)	#IMPLIED" >

<!ENTITY % SMILtimeVal	"CDATA" >
<!ENTITY % uri		"CDATA" >
<!ENTITY % script	"CDATA" >

<!-- ELEMENTS -->

<!-- Top Level NCX Container. -->
<!ELEMENT ncx (head, docTitle, docAuthor*, navMap, navList*)>
<!ATTLIST ncx 
  version     CDATA     #FIXED "1.0.0"
  %i18n;
>

<!-- Document Head - Contains all NCX metadata.  
-->

<!ELEMENT head (smilCustomTest | meta)+>

<!-- smilCustomTest - Duplicates customTest data found in SMIL files.  Each unique customTest element that appears in one or more SMIL files must have its attributes duplicated in a smilCustomTest element in the NCX.  The NCX thus gathers in one place all customTest elements used in the SMIL files, for presentation to the user.
-->
<!ELEMENT smilCustomTest EMPTY>
<!ATTLIST smilCustomTest
id		ID		#REQUIRED
defaultState	(true|false) 	'false'
override	(visible|hidden) 'hidden'>  

<!-- Meta Element - metadata about this NCX -->
<!ELEMENT meta EMPTY>
<!ATTLIST meta
  name		CDATA		#REQUIRED
  content	CDATA		#REQUIRED
  scheme	CDATA		#IMPLIED
>

<!-- DocTitle - the title of the document, required and must immediately follow head. 
-->

<!ELEMENT docTitle (text, audio?)>
<!ATTLIST docTitle
  id		ID		#IMPLIED
  %i18n;
>

<!-- DocAuthor - the author of the document, immediately follows docTitle.
-->

<!ELEMENT docAuthor (text, audio?)>
<!ATTLIST docAuthor
  id		ID		#IMPLIED
  %i18n;
>

<!-- Navigation Structure - container for all of the NCX objects that are part of the hierarchical structure of the document.
-->

<!ELEMENT navMap (navLabel*, navPoint+)>
<!ATTLIST navMap
  id		ID		#IMPLIED
>

<!-- Navigation Point - contains description(s) of target, as well as a pointer to entire content of target.
Hierarchy is represented by nesting navPoints.  "class" attribute describes the kind of structural unit this object represents (e.g., "chapter", "section").  "value" attribute is a numerical representation of the text content of the
label if this is a purely numerical (integer only) label (e.g., a page number).  "pageRef" is the id of the page navTarget on which this structure target begins.
-->
<!ELEMENT navPoint (navLabel+, content, navPoint*)>
<!ATTLIST navPoint
  id		ID			#REQUIRED
  onFocus	%script;	#IMPLIED
  onBlur	%script;	#IMPLIED
  class		CDATA		#IMPLIED
  value		CDATA		#IMPLIED
  pageRef	IDREF		#IMPLIED
>

<!-- Navigation List - container for distinct, flat sets of navigable elements, e.g.  page numbers, 
notes, figures, tables, etc.  Essentially a flat version of navMap.  The "class" attribute describes the type of object contained in this navList, using dtbook element names, e.g., pagenum, note.
-->

<!ELEMENT navList   (navLabel+, navTarget+) >
<!ATTLIST navList
  id		ID		#IMPLIED
  class		CDATA		#IMPLIED
>

<!-- Navigation Target - contains description(s) of target, as well as a pointer to entire content of target.
navTargets are the equivalent of navPoints for use in navLists. "mapRef" is the id of another navPoint within this NCX that contains this navTarget.  "class" attribute describes the kind of structure this target represents, using its dtbook element name, e.g., pagenum, note.
-->

<!ELEMENT navTarget  (navLabel+, content) >
<!ATTLIST navTarget
  id		ID		#REQUIRED
  onFocus	%script;	#IMPLIED
  onBlur	%script;	#IMPLIED 
  class		CDATA		#IMPLIED
  value		CDATA		#IMPLIED
  mapRef	IDREF		#REQUIRED
>

 
<!-- Navigation Label - Contains a description of a given <navMap>, <navPoint>, <navList>, or <navTarget> in various media for presentation to the user. Can be repeated so descriptions can be provided in multiple languages. -->
<!ELEMENT navLabel ((text,(audio?, img?))|((text?), audio, (img?))) >
<!ATTLIST navLabel
	%i18n; 
>


<!-- Content Element - pointer into SMIL to beginning of navPoint. -->
<!ELEMENT content EMPTY>
<!ATTLIST content
  id		ID		#IMPLIED
  src		%uri;		#REQUIRED
>

<!-- Text Element - Contains text of docTitle, navPoint heading, navTarget (e.g., page number), or label for navMap or navList. -->
<!ELEMENT text (#PCDATA)>
<!ATTLIST text
  id		ID				#IMPLIED
  class	CDATA			#IMPLIED
>

<!-- Audio Element - audio clip of navPoint heading. -->
<!ELEMENT audio EMPTY>
<!ATTLIST audio
  id		ID				#IMPLIED
  class	CDATA			#IMPLIED
  src		%uri;			#REQUIRED
  clipBegin	%SMILtimeVal;	#IMPLIED
  clipEnd	%SMILtimeVal;	#IMPLIED
>

<!-- Image Element - image that may accompany heading. -->
<!ELEMENT img EMPTY>
<!ATTLIST img
  id		ID			#IMPLIED
  class	CDATA		#IMPLIED
  src		%uri;		#REQUIRED
>


Contents

Appendix 4 - DTD for Portable Bookmarks/Highlights

(This section is normative.)


<!-- bookmark 1.0.0 DTD 2001-09-27
file: bookmark100.dtd  
   
Authors: Tom McLaughlin and Michael Moodie


The following identifiers apply to this DTD: 
"-//NISO//DTD bookmark v1.0.0//EN"
"http://www.loc.gov/nls/z3986/v100/bookmark100.dtd"   
-->  

      
<!-- ********************* Entities ******************* -->
<!ENTITY % uri "CDATA">
<!-- ********************* Elements ********************* -->
<!-- BookmarkSet: The set of bookmarks for a book consists of the title, a unique identifier of the book, the last place the reader left off and zero or more bookmarks, highlights, and associated audio or textual notes. This set is intended for export of bookmarks, highlights and notes to another player; the markup is not required for a player's internal representation of bookmarks.
 -->
<!ELEMENT bookmarkSet	(title, uid, lastmark?, (bookmark | hilite)*) >
<!-- Title: The book's title in text and an optional audio clip.
 -->
<!ELEMENT title	(text, audio?) >

<!-- uid: A globally unique identifier for the book.
 -->
<!ELEMENT uid	(#PCDATA) >

<!-- Bookmark: Location and optional note. Location consists of a uri pointing to the id attribute of the <par> element in the SMIL file that contains the bookmark plus a time offset in seconds (or character offset) to the exact place.  Player should by default automatically number bookmarks in the order in which they fall in the book.
 -->
<!ELEMENT bookmark	(ncxRef, uri, (timeOffset | charOffset), note?) >
<!ATTLIST bookmark
	label		CDATA		#IMPLIED
>  

<!-- NcxRef: Captures current location in NCX (the id of the current navPoint)at time lastmark, bookmark, or highlight is set.  Ensures that current location in NCX and SMIL are synchronized after moving to a lastmark, etc., so that any global navigation commands issued by the user will start from the current location. -->
<!ELEMENT ncxRef       (#PCDATA)>

<!-- Lastmark: Location where reader left off and where player will resume play when restarted.
 -->
<!ELEMENT lastmark	(ncxRef, uri, (timeOffset | charOffset)) >

<!-- Hilite: A block of text with an optional note attached.
 -->
<!ELEMENT hilite	(hiliteStart, hiliteEnd, note?) >
<!ATTLIST hilite
	label		CDATA		#IMPLIED
>  

<!-- HilStart: Starting point of highlighted block.
 -->
<!ELEMENT hiliteStart	(ncxRef, uri, (timeOffset | charOffset)) >

<!-- HilEnd: End point of highlighted block.
 -->
<!ELEMENT hiliteEnd		(ncxRef, uri, (timeOffset | charOffset)) >

<!-- Uri: pointer to id of <par> or <seq> in SMIL, to id in text-only file, or to audio file that contains the bookmark.
 -->
<!ELEMENT uri	(#PCDATA) >

<!-- Timeoffset: Exact position of bookmark in SMIL file or audio-only file referenced by the uri; in seconds.fraction (seconds=DIGIT+, fraction=3DIGIT).
 -->
<!ELEMENT timeOffset	(#PCDATA) >

<!-- Charoffset: Exact position of bookmark in text-only file referenced by the uri: in characters, counting from nearest previous tag with an id.  White space is normalized (collapsed to one character) and tags are not counted.
 -->
<!ELEMENT charOffset     (#PCDATA) >

<!-- Note: The note is for the user's input, random thoughts, musings, etc. It can be text or audio or both.
 -->
<!ELEMENT note		(text?, audio?) >

<!-- Text: Text of title or note. 
 -->
<!ELEMENT text	(#PCDATA) >
<!-- Audio: Audio clip of user-recorded note, in any format supported by standard.
 -->
<!ELEMENT audio	EMPTY >
<!ATTLIST audio
	
   src         %uri;    #REQUIRED
   clipBegin   CDATA    #IMPLIED
   clipEnd     CDATA    #IMPLIED
>

Contents

Appendix 5 - DTD for Resource File

(This section is normative.)


<!-- Resource File 1.0.0 DTD 2001-09-27
 file: resource100.dtd  
 
Authors: Tom McLaughlin, Michael Moodie, Thomas Kjellberg Christensen

The following identifiers apply to this DTD: 
"-//NISO//DTD resource v1.0.0//EN"
"http://www.loc.gov/nls/z3986/v100/resource100.dtd"
-->

<!-- ********** Attribute Types *********** -->
<!-- languagecode: An RFC1766 language code. -->
<!ENTITY % languagecode "NMTOKEN">

<!-- SMILtimeVal: SMIL 2.0 clock value. -->
<!ENTITY % SMILtimeVal "CDATA">

<!ENTITY % URI "CDATA">

<!-- **************** Resource Elements ********** -->

<!-- Resources: Root element of DTD. 
-->
<!ELEMENT resources  (head?, (resource)+) >
<!ATTLIST resources
  version   	CDATA       	#FIXED "1.0.0"
>

<!-- Document Head - Contains metadata. 
-->
<!ELEMENT head (meta*)>

<!-- Resource element contains information about the alternative representations 
of an element present in the NCX or the textual content file. An alternative 
representation can be used to convey navigational information, e.g., provide 
a descriptive name for the kind of segment (part, chapter, section, etc.) 
the user is encountering.  In addition, it can supply accessible versions of dtbook element names and names of skippable structures listed in the head of the NCX.  Text can be used for screen or braille display, 
audio for digital talking book players, and image for screen display.
Attribute use:
type - Specifies whether the resource applies to the textual content file (dtbook) or the NCX 
(ncx). 
elementRef - Specifies the name of the element for which the resource is to be supplied.      classRef - Specifies the class attribute value of the element for which the resource is to be supplied. 
idRef - Specifies the name of the id attribute on the smilCustomTest element in NCX for which the resource is to be supplied. 
lang - Specifies the language of the resource item, using an RFC 1766 language code.
-->

<!ELEMENT resource  ((text, audio?, img?) | (text?, audio, img?)) >
<!ATTLIST resource
  type		(ncx | dtbook)	#REQUIRED
  elementRef   	CDATA       	#REQUIRED
  classRef	CDATA		#IMPLIED
  idRef		CDATA		#IMPLIED
  lang     	%languagecode;  #IMPLIED
>

<!ELEMENT text  (#PCDATA) >
 
<!ELEMENT audio  EMPTY > 
<!ATTLIST audio 
  src		%URI;		#REQUIRED 
  clipBegin	%SMILtimeVal;	#IMPLIED 
  clipEnd	%SMILtimeVal;	#IMPLIED 
> 
 
<!-- If the clipBegin attribute is not present in an instance of the 
audio element, the audio file referenced must be played from its beginning.  
If the clipEnd attribute is not present, the audio file must be played to 
its end. If the value of the clipEnd attribute exceeds the duration of 
the audio file, the value must be ignored, and the audio file played to 
its end.
--> 
 
<!ELEMENT img  EMPTY > 
<!ATTLIST img
  src		%URI;		#REQUIRED
>
 
<!-- Meta Element - producer-defined metadata about this resource file.
--> 
<!ELEMENT meta EMPTY> 
<!ATTLIST meta
  name		CDATA		#REQUIRED
  content	CDATA		#REQUIRED
  scheme	CDATA		#IMPLIED
>

Contents

Appendix 6 - Distribution Information DTD

(This section is normative.)



<!-- distInfo 1.0.0 DTD 2001-09-27
file: distInfo100.dtd 

Author: James Pritchett

Description:
An XML application to describe the contents of a single piece of DTB
distribution media.  It consists of a list of books to be found on the
media.  For each book, distInfo identifies the location of each book 
within the media filesystem.  If the book is being distributed on multiple 
distribution media (media units), the distInfo book element also includes:
1) the sequence id of this media unit
2) a distribution map for the book, telling where to find all the SMIL files for a book

The following identifiers apply to this DTD: 
"-//NISO//DTD distInfo v1.0.0//EN"
"http://www.loc.gov/nls/z3986/v100/distInfo100.dtd"

-->
<!-- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * -->

<!ENTITY % URI 		"CDATA">
<!ENTITY % SMILtimeVal	"CDATA">

<!-- distInfo:  Root element, consists of one or more books.
"version" specifies the version of this DTD used in this instance. Three 
digits, with decimal point separators; digits one, two and three will 
reflect major, moderate and minor changes, respectively. This attribute 
must be present but parsers will not enforce its presence, just its value.
-->
<!ELEMENT distInfo (book+)>
<!ATTLIST distInfo
	version		CDATA		#FIXED "1.0.0"
>

<!-- book:  a DTB that is present, in part or whole, on this piece of
distribution media.  The uid and pkgRef attributes are required.  "uid"
matches the package unique-identifier.  "pkgRef" is a URI that locates the
book's package file on this media unit.

If this is a book fragment, then the "media" attribute identifies which
fragment is stored on this media unit, and a single distMap element
is present to describe which SMIL files are present on which media units.
The media attribute is in the format "x:y", where x is the sequence
number of this media unit, and y is the total number of media units
in the distribution of this book.

In the case of a book fragment, <book> should contain exactly one 
<distMap> and optionally one or more <changeMsg> elements.
-->
<!ELEMENT book (distMap?, changeMsg*)>
<!ATTLIST book
	uid		CDATA		#REQUIRED
	pkgRef		CDATA		#REQUIRED
	media		CDATA		#IMPLIED
>

<!-- distMap:  a map identifying which media the various SMIL files
reside upon.  This consists of one or more smilRef elements.  The
distMap smilRef's should match one-to-one those of the book package spine.
-->
<!ELEMENT distMap (smilRef+)>

<!-- smilRef:  a reference to a DTB SMIL file.  These are referenced
by file name. The mediaRef attribute of each smilRef identifies the piece of 
media that the file resides upon, and is in the format "x:y" (see above).
-->
<!ELEMENT smilRef EMPTY>
<!ATTLIST smilRef
	file		CDATA		#REQUIRED
	mediaRef	CDATA 		#REQUIRED
>

<!-- changeMsg:  A pointer to a custom message to be read when a new disk is
requested by the reading system.  "mediaRef" identifies the media unit which 
this message (e.g.,"Insert disc 2") specifies.  Player invokes the correct 
<changeMsg> by matching its "mediaRef" attribute to the "mediaRef" attribute 
of the selected <smilRef>.  "mediaRef" is in the format "x:y", where x is 
the sequence number of the specified media unit, and y is the total number of media 
pieces in the distribution of this book. 
-->
<!ELEMENT changeMsg ((text, audio?) | (text?, audio))>
<!ATTLIST changeMsg
	mediaRef	CDATA		#REQUIRED
	lang 		NMTOKEN 	#IMPLIED 
>

<!-- text: Contains text of media change message.
-->
<!ELEMENT text (#PCDATA)>

<!-- audio: Pointer to audio content of media change message.
-->
<!ELEMENT audio EMPTY>
<!ATTLIST audio
	src		%URI;			#REQUIRED
	clipBegin	%SMILtimeVal;		#IMPLIED
	clipEnd		%SMILtimeVal;		#IMPLIED
>


Contents

Appendix 7 - Designation of Maintenance Agency

(This Appendix is not part of American National Standard Z39.86-200x v1.0.0, File Specifications for the Digital Talking Book. It is included for information only.)

The functions assigned to the maintenance agency as specified in section 1.7 will be administered by the National Library Service for the Blind and Physically Handicapped, the Library of Congress. Questions concerning the implementation of this standard and requests for information should be sent to the Research and Development Officer, National Library Service for the Blind and Physically Handicapped, Library of Congress, Washington, DC 20542, or nls@loc.gov, including "Z3986" in the subject line.

Contents