Subject

Definition

These are theme or topic keywords.

Instructions

This field is indexed as a facet by default for GeoBlacklight applications, and it can become unwieldy when aggregating metadata records from multiple sources. Controlled vocabularies for GIS data have typically been expressed as ISO Topic Categories and localized thesauri, while scanned maps are typically described with Library of Congress Subject Headings. Even within these vocabularies, localized spellings and abbreviations will result in considerable variations between institutions. Institutions are encouraged to observe what terms are commonly in use and, at the very least, strive for internal consistency with controlled vocabularies and spellings. This facilitates easier metadata sharing across projects, such as the repositories in OpenGeoMetadata. Some institutions choose to create custom keyword fields to hold local, unnormalized values. It is recommended not to use Library of Congress Subject Headings to indicate the geography or spatial coverage of a dataset; instead, use the dct_spatial_sm field for this.

Examples

Census
Human settlements