WhatIsCoreMetadata

Basic Rules of Core Metadata

Core metadata is the universal description of a particular collection. This universal description is provided by a combination of field:value pairs. There are two MANDATORY fields.

• dc:identifier that uniquely identifies the collection in the ldr metadata storage system
• EITHER dc:isPartOf OR dc:hasPart with xsi:type dcterms:URI that defines the relationship of the collection in a hierarchy of collections. Every collection in the metadatastorage system has at least one hierarchical relationship to another collection: the root (or LDR) collection.

in addition to the required fields, there are are five OPTIONAL fields. These fields can be added at the record creator's discretion. The rule of thumb for the creator to follow when deciding whether or not to add one of these fields: does it provide a relevant intellectual access point to this collection?

• dc:title which is the primary intellectual access point
• dc:creator which is a secondary intellectual access point
• dc:date which is a secondary intellectual access point
• dc:subject which is a secondary intellectual access point
• dc:description which is a human-readable explanation about the collection
• dc:relation with xsi:type=dcterms:URI

A core metadata record is made up of at least the MANDATORY fields and any or none of the OPTIONAL fields. This is the metadata that is offered to consuming clients in order to provide cross-browsing across collections.

Core metadata is stored as a collection containing two elements

• dc:identifier
• dc:type with value "core"
• EITHER dc:hasPart OR dc:partOf OR both
• any combination of the OPTIONAL fields

It looks like the following sample record, which has an identifier of "biz-bob" that uniquely identifies it in the context of the metadatastorage system. The sample record also has a part that is a URL to a remote byte stream, but it also has another part that is a URI to a subordinate collection while simultaneously being part of a superior collection "biz".

<collection>
    <dc:identifier>biz-bob</dc:identifier>
    <dc:hasPart xsi:type="dcterms:URL">http://example.com</dc:hasPart>
    <dc:isPartOf xsi:type="dcterms:URI">/collection/biz</dc:isPartOf>
    <dc:hasPart xsi:type="dcterms:URI">/collection/bar</dc:isPartOf>
    <dc:type>core</dc:type>
</collection>