How to relate complex parts and instantiations

PBCore may be used to express multiple instantiations per work (e.g., multiple tapes containing one program). It may be done in different ways, depending on what – if any – descriptive metadata should accompany each tape.

If metadata to describe the content of each tape (i.e., the program segment material) is not needed, then the program can be described generally at the level of element ‘pbcoreDescriptionDocument,’ and each of its multiple carriers noted most simply by the repeated use of the sub-element structure within pbcoreInstantiation. For example:

<?xml version="1.0" encoding="UTF-8"?>
<pbcoreDescriptionDocument xmlns="http://pbcore.org/PBCore/PBCoreNamespace.html"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://pbcore.org/PBCore/PBCoreNamespace.html>
<pbcoreIdentifier source="MARS">XYZ123</pbcoreIdentifier>
    <pbcoreTitle>XYZ123:  The Program</pbcoreTitle>

<!-- section removed for clarity -->

    <pbcoreInstantiation>
        <instantiationIdentifier source="MARS">XYZ123-A</instantiationIdentifier>
        <instantiationLocation>VAULT</instantiationLocation>
        <instantiationRelation>
            <instantiationRelationType annotation="One of a multi-part instantiation">Precedes in Sequence</instantiationRelationType>
            <instantiationRelationIdentifier source="MARS">XYZ123-B</instantiationRelationIdentifier>
        </instantiationRelation>
    </pbcoreInstantiation>
    <pbcoreInstantiation>
        <instantiationIdentifier source="MARS"></instantiationIdentifier>
        <instantiationLocation>VAULT</instantiationLocation>
        <instantiationRelation>
            <instantiationRelationType annotation="One of a multi-part instantiation">Follows in Sequence</instantiationRelationType>
            <instantiationRelationIdentifier source="MARS">XYZ123-A</instantiationRelationIdentifier>
        </instantiationRelation>
        <instantiationRelation>
            <instantiationRelationType annotation="One of a multi-part instantiation">Precedes in Sequence</instantiationRelationType>
            <instantiationRelationIdentifier source="MARS">XYZ123-C</instantiationRelationIdentifier>
        </instantiationRelation>
    </pbcoreInstantiation>

<!-- section removed for clarity -->

</pbcoreDescriptionDocument>

If descriptive metadata about the program material is needed at the level of the tape, then use pbcoreDescriptionDocument as before, but with sub-elements ‘pbcorePart’ instead of ‘pbcoreInstantiation.’ There, data about each tape would be contained within pbcorePart structures, each with a ‘pbcoreInstantiation’ assemblage:

<?xml version="1.0" encoding="UTF-8"?>
<pbcoreDescriptionDocument xmlns="http://pbcore.org/PBCore/PBCoreNamespace.html"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://pbcore.org/PBCore/PBCoreNamespace.html>
<pbcoreIdentifier source="MARS">XYZ123</pbcoreIdentifier>
    <pbcoreTitle>XYZ123:  The Program</pbcoreTitle>

<!-- section removed for clarity -->

    <pbcorePart startTime="00:00:00" endTime="00:29:50">
        <pbcoreIdentifier source="MARS">XYZ123-A</pbcoreIdentifier>
        <pbcoreTitle>XYZ123: The Program Part One</pbcoreTitle>
        <pbcoreDescription>The stage is set for conflict between X, Y and Z</pbcoreDescription>
        <pbcoreInstantiation>
            <instantiationIdentifier source="MARS" annotation="One of a multi-part instantiation">XYZ123-A</instantiationIdentifier>
            <instantiationLocation>VAULT</instantiationLocation>
            <instantiationRelation>
                <instantiationRelationType annotation="One of a multi-part instantiation">Precedes in Sequence</instantiationRelationType>
                <instantiationRelationIdentifier source="MARS">XYZ123-B</instantiationRelationIdentifier>
            </instantiationRelation>
        </pbcoreInstantiation>       
    </pbcorePart>

    <pbcorePart startTime="00:29:50" endTime="00:59:40">
        <pbcoreIdentifier source="MARS">XYZ123-B</pbcoreIdentifier>
        <pbcoreTitle>XYZ123: The Program Part Two</pbcoreTitle>
        <pbcoreDescription>The forces of X, Y and Z combine to shake the world</pbcoreDescription>
        <pbcoreInstantiation>
            <instantiationIdentifier source="MARS" annotation="One of a multi-part instantiation">XYZ123-B</instantiationIdentifier>
            <instantiationLocation>VAULT</instantiationLocation>
            <instantiationRelation>
                <instantiationRelationType annotation="One of a multi-part instantiation">Follows in Sequence</instantiationRelationType>
                <instantiationRelationIdentifier source="MARS">XYZ123-A</instantiationRelationIdentifier>
            </instantiationRelation>
        </pbcoreInstantiation>       
    </pbcorePart>

<!-- section removed for clarity -->

</pbcoreDescriptionDocument>