Representing parts of a digital object

The structural divisions of the hierarchical organization provided by a <structMap> are represented by division <div> elements, which can be nested to any depth. Each <div> element can represent either an intellectual (logical) division or a physical division. It can explicitly identify the form of <div> it represents via its TYPE attribute. Thus in the case of a digitized book subdivided by the <structMap> into nested <div> elements representing chapters and then pages, the TYPE attribute values of the <div> elements at each successive level of the hierarchy might be “book”, “chapter”, and “page”.

The optional LABEL attribute value can identify a <div> element in a specific manner suitable for presentation to the user of the digital object. So, a hierarchical presentation of the <div> LABEL attribute values would typically form a kind of “table of contents” that digital library patrons could use to comprehend and navigate the content represented by a digital object encoded using METS. The LABEL attribute could, of course, serve different purposes in different applications of the METS standard.

<fileGrp> may point to pertinent metadata groups <mdGrp> and metadata elements <md> in the Metadata Section <mdSec> of the METS document by means of an MDID attribute.

A <div> element at any level can be associated with one or more metadata groups <mdGrp> and metadata elements <md> in the Metadata Section <mdSec> of the METS document by means of its MDID attribute. It is assumed that any metadata referenced by a <div> element pertains to the division as a whole. For example: the root <div> in a digital object encoded using METS that represents a video might point to a <md> element that expresses the copyright and access restriction information for the entire video.

Example

The simple encoding fragment below demonstrates the div features described thus far, including the TYPE, LABEL, and MDID attributes.

<?xml version="1.0" encoding="UTF-8"?>
<mets:mets xmlns:mets="http://www.loc.gov/METS/v2"
    xmlns:mods="http://www.loc.gov/mods/v3"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.loc.gov/METS/v2
      http://www.loc.gov/standards/mets/mets.xsd
      http://www.loc.gov/mods/v3 http://www.loc.gov/mods/v3/mods-3-1.xsd"
    OBJID="ark:/13030/kt9s2009hz" LABEL="Martial Epigrams">
  <mets:mdSec>
    <mets:md ID="DMD1" USE="DESCRIPTIVE">
      <mets:mdWrap MDTYPE="MODS">
        <mets:xmlData>
          <mods:mods>
            <mods:titleInfo>
              <mods:title>Martial Epigrams</mods:title>
            </mods:titleInfo>
          </mods:mods>
        </mets:xmlData>
      </mets:mdWrap>
    </mets:md>
  </mets:mdSec>
  [...]
  <mets:structSec>
    <mets:structMap TYPE="physical">
      <mets:div TYPE="book" LABEL="Martial Epigrams II" MDID="DMD1">
        <mets:div TYPE="page" LABEL="Blank page"/>
        <mets:div TYPE="page" LABEL="Page i: Series title page"/>
        <mets:div TYPE="page" LABEL="Page ii: Blank page"/>
        <mets:div TYPE="page" LABEL="Page iii: Title page"/>
        <mets:div TYPE="page" LABEL="Page iv: Publication info"/>
        <mets:div TYPE="page" LABEL="Page v: Table of contents"/>
        <mets:div TYPE="page" LABEL="Page vi: Blank page"/>
        <mets:div TYPE="page" LABEL="Page 1: Half title page"/>
        <mets:div TYPE="page" LABEL="Page 2 (Latin)"/>
        <mets:div TYPE="page" LABEL="Page 3 (English)"/>
        <mets:div TYPE="page" LABEL="Page 4 (Latin)">
        <mets:div TYPE="page" LABEL="Page 5 (English)"/>
        <mets:div TYPE="page" LABEL="Page 6 (Latin)"/>
        <mets:div TYPE="page" LABEL="Page 7 (English)"/>
      </mets:div>
    </mets:structMap>
  </mets:structSec>
</mets:mets>

Through its subsidiary elements, each <div> element points to the digital content that manifests it. It can do so through one or more <mptr> element, if this content is represented by one or more external METS documents, or through one or more <fptr> element, if this content is represented by one or more <file> elements in the <fileSec> In addition to or instead of directly pointing to digital content via its child <fptr> and/or <mptr> elements, a <div> element may itself contain <div> elements that further subdivide the content represented by the division.