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NIMAS Technical Specification

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This is an annotated version of the NIMAS 1.1 Technical Specification to explain changes and corrections that have been made to the Standard since publication in the Federal Register. Changes represent clarification of or additional information about parts of the Specification or items that have been determined in practice since its original publication.  Please contact the AEM Center for assistance in interpreting the Technical Specification.

The Baseline Element Set

The Baseline Element Set details the minimum requirement that must be delivered to fulfill the NIMAS requirement. It is the responsibility of publishers to provide this NIMAS-conformant XML content file, a package file (OPF), a PDF-format copy of the title page (or whichever page(s) contain(s) ISBN and copyright information), and a full set of the content's images. All of the images included within a work must be provided in a folder and placeholders entered in the relevant XML document indicating their location (all images must be included). The preferred image type is SVG, next is either PNG or JPG format. Images should be rendered in the same size/proportion as their originals at 300 dpi. Images should be named with relative path filenames in XML files (example: <img id="staricon4" src="./images/U10C02/staricon4.jpg" alt="star icon"/>).

Annotation: Language pertaining to images has been clarified to explain size and resolution guidelines and the fact that images present in a source work are required as part of a NIMAS fileset.

NIMAS-conformant content must be valid to the NIMAS 1.1 [see DAISY/NISO Z39.86 2005 or subsequent revisions]. In addition, files are required to use the tags from the Baseline Element Set when such tags are appropriate. Publishers are encouraged to augment the required Baseline Element Set with tags from the Optional Element Set (elements not included in the Standard) as applicable. For the purposes of NIMAS, appropriate usage of elements, both baseline and optional, is defined by the DAISY Structure Guidelines. Files that do not follow these guidelines in the selection and application of tags are not conformant to this Standard. Both optional elements and appropriate structure guidelines may be located within Z39.86-2002 and Z39.86-2005 available from Specifications for the Digital Talking Book. Use of the most current standard is recommended.

A typo was corrected to show that NIMAS 1.1 aligns to DAISY/NISO Z39.86 2005 (not ANZI/NISO).

a. Document-level tags

The root element in the Digital Talking Book DTD. <dtbook> contains metadata in <head> and the contents itself in <book>.

This element should be empty for a NIMAS file.

Annotation: Note about the <head> tag being empty in a NIMAS file was added.

Surrounds the actual content of the document, which is divided into <frontmatter>, <bodymatter>, and <rearmatter>. <head>, which contains metadata, precedes <book>.

b. Structure and hierarchy

Usually contains <doctitle> and <docauthor>, as well as preliminary material that is often enclosed in appropriate <level> or <level1> etc. Content may include a copyright notice, a foreword, an acknowledgements section, a table of contents, etc. <frontmatter> serves as a guide to the content and nature of a <book>.

Annotation: Currently must appear as the first element within source files. (This was not yet required when the Standard was first published.)

Consists of the text proper of a book, as contrasted with preliminary material <frontmatter> or supplementary information in <rearmatter>.

Contains supplementary material such as appendices, glossaries, bibliographies, and indices. It follows the <bodymatter> of the book.

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>.

Annotation: Typos (duplicate word, missing letter) were corrected in the description: "rearmatter ", "bodymater".

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

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.

Contains further subdivisions that nest within <level3> subdivisions. The class attribute identifies the actual name of the subordinate structure it marks.

Contains further subdivisions that nest within subdivisions. The class attribute identifies the actual name of the subordinate structure it marks.

Contains further subdivisions that nest within subdivisions. The class attribute identifies the actual name of the subordinate structure it marks.

Contains the text of the heading for a structure.

Contains the text of the heading for a structure.

Contains the text of the heading for a structure.

Contains the text of the heading for a structure.

Contains the text of the heading for a structure.

Contains the text of the heading for a structure.

c. Block elements

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> and <cite>.

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.

Contains some form of list, ordered or unordered. The list may have an 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.

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.

Marks the text of a heading in a <list> or <sidebar>.

Annotation: A typo was deleted from the description: "or \ <".

Marks a footnote, endnote, etc. Any local reference to <note id="yyy"> is by <noteref idref="#yyy"">. [Attribute id]

Contains a paragraph, which may contain subsidiary <list> or <dl>.

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>.

Marks a reference (or citation) to another document.

Marks a definition of the preceding term <dt> within a definition list <dl>. A definition without a preceding <dt> has no semantic interpretation, but is visually presented aligned with other <dd>.

Contains a definition list, usually consisting of pairs of terms <dt> and definitions <dd>. Any definition can contain another definition list.

Marks a term in a definition list <dl> for which a definition <dd> follows.

d. Inline elements

Indicates emphasis. Usually <em> is rendered in italics. Compare with <strong>.

Contains a short, inline quotation. Compare with <blockquote>, which marks a longer quotation set off from the surrounding text.

Marks stronger emphasis than <em>. Visually <strong> is usually rendered bold.

Indicates a subscript character (printed below a character's normal baseline). Can be used recursively and/or intermixed with <sup>.

Marks a superscript character (printed above a character's normal baseline). Can be used recursively and/or intermixed with <sub>.

Marks a forced line break.

Marks a single logical line of text. Often used in conjunction with in documents with numbered lines. [Use only when line breaks must be preserved to capture meaning (e.g., poems, legal texts).]

Contains a line number, for example in legal text. [Use only when is used, and only for lines numbered in print book.]

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. [NB: Only valid when it includes an id attribute].

Marks one or more characters that reference a footnote or endnote.

e. Tables

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.

Indicates a table cell containing data.

Marks one row of a <table> containing <th> or <td> cells.

f. Images

Provides a container for one or more <img> and associated <caption>(s) and <prodnote>(s). A <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 imgref="id1 id2 ...">, 2) multiple <caption> if several captions refer to a single <img id="xxx"> where each caption has the same <caption imgref="xxx">, 3) multiple <prodnote> if different versions are needed for different media (e.g., large print, braille, or print). If several <prodnote> refer to a single <img id="xxx">, each prodnote has the same <prodnote imgref="xxx">.

Points to the image to be rendered. An <img> may stand alone or be grouped using <imggroup>.

Describes a <table> or <img>. If used with <table> it must follow immediately after the <table> start tag. If used with <imggroup> it is not so constrained.

Optional Elements and Guidelines for Use

Publishers are encouraged to apply mark-up beyond the baseline (required) elements. The complete DTBook Element Set reflects the tags necessary to create the six types of Digital Talking Books and Braille output. Because of the present necessity to subdivide the creation of alternate format materials into distinct phases, the Panel determined that baseline elements would be provided by publishers, and optional elements would be added to the NIMAS-conformant files by third-party conversion entities. In both circumstances the protocols for tagging digital files should conform to the most current DAISY/NISO Z39.86 specification. Content converters are directed to the most current DAISY Structure Guidelines for guidance on their use.

Annotation: A link to the most recent version of the DAISY Structure Guidelines was added.

Since the publication of the original National File Format report from which the NIMAS technical specifications were derived, ANSI/NISO Z39.86-2002 was updated and is now DAISY/NISO Z39.86-2005. It may be best to avoid using the following optional elements which are no longer included in DAISY/NISO Z39.86-2005: <style>, <notice>, <hr>, and <levelhd>.

Also, the following new elements were introduced by DAISY/NISO Z39.86-2005 and should be considered optional elements for the NIMAS: <bridgehead>, <byline>, <covertitle>, <dateline>, <epigraph>, <linegroup>, and <poem>. Please refer to DAISY/NISO Z39.86-2005 for additional information regarding these elements. 

Package File

A package file describes a publication. It identifies all other files in the publication and provides descriptive and access information about them. A publication must include a package file conforming to the NIMAS. The package file is based on the Open eBook Publication Structure 1.2 package file specification (For most recent detail please see A NIMAS package file must be a valid XML OeBPS 1.2 package file instance and must meet the following additional standards:

Annotation: A typo was corrected in the wording of this section of the Standard to clarify that a NIMAS OPF file must be a valid XML OeBPS 1.2 package file. NIMAS package files must also conform to NIMAC metadata requirements. (The NIMAC had not yet established their specific metadata requirements when the Standard was first published.)

The NIMAS Package File must include the following Dublin Core (dc:) metadata:

  • dc:Title
  • dc:Creator (if applicable)
  • dc:Publisher
  • dc:Date (Date of NIMAS-compliant file creation—yyyy-mm-dd)
  • dc:Format (="NIMAS 1.1")
  • dc:Identifier (a unique identifier for the NIMAS-compliant digital publication, e.g., print ISBN + "-NIMAS"—exact format to be determined)
  • dc:Language (one instance, or multiple in the case of a foreign language textbook, etc.)
  • dc:Rights (details to be determined)
  • dc:Source (ISBN of print version of textbook)

Annotation: A typo was corrected to show that the current specification is NIMAS 1.1, not NIMAS 1.0, and a typo was corrected to add a missing space. The precise format of the dc: Identifier metadata element had not yet been established when the Standard was first published. The example here provides a practical model.

<dc: Identifier> exact format has been determined as follows:
<dc:Identifier id="id">
where the zeroes are the print work's ISBN followed by the text "NIMAS" without punctuation.

And the following x-metadata items:

  • nimas-SourceEdition (the edition of the print textbook)
  • nimas-SourceDate (date of publication of the print textbook)

The following metadata were proposed also as a means of facilitating recordkeeping, storage, and file retrieval:

  • dc:Subject (Language Arts, Social Studies, etc.)
  • nimas-grade (specific grade level of the print textbook, e.g.; Grade 6)
  • nimas gradeRange (specific grade range of the print textbook, e.g.; Grades 4–5)

Annotation: For the final metadata requirements and guidance for supplying NIMAS metadata, please refer to the NIMAC Metadata Guidelines.

Annotation: One item determined since original publication of the Standard is the correct MIME type format to use in NIMAS package files, as the use of established MIME types in OPF files is required for NIMAS fileset package files. The correct types for the most-commonly used formats are as follows:
XML: "media-type="application/x-dtbook+xml"
PDF: "media-type="application/pdf"
images: "media-type="image/jpeg", "media-type="image/svg+xml", "media-type= "image/png"

Modular Extensions

The most current DAISY/NISO standard, formally the DAISY/NISO Z39.86, Specifications for the Digital Talking Book defines a comprehensive system for creating Digital Talking Books. A part of this standard is DTBook, an XML vocabulary that provides a core set of elements needed to produce most types of books. However, DTBook is not intended to be an exhaustive vocabulary for all types of books.

Guidelines for the correct approach to extend the DAISY/NISO standard have been established. Mathematics, video support, testing, workbooks, music, dictionaries, chemistry, and searching are some of the extensions that have been discussed. Visit Guidelines for Modular Extensions to Z39.86 for more information. 

Related resources


Creating NIMAS Files

Practical information about creating a NIMAS fileset for publishers and conversion houses.

AEM Center at CAST


NIMAS Files Best Practices

Best practices for preparing NIMAS filesets when textbooks are adopted or purchased.

AEM Center at CAST

NIMAS Exemplars

Review exemplars that illustrate NIMAS best practices.

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