Schlagwortkatalog

Schlagwortkatalog is a library cataloging approach in which bibliographic records are indexed primarily by Schlagwörter, or subject terms, rather than by author or title alone. In such catalogs, each work is linked to standardized terms that describe its topics, themes, or content. This enables retrieval by topic, facilitates browsing through related terms, and supports finding related works via hierarchical relationships and cross-references.

Structure and terminology: Schlagwörter are drawn from controlled vocabularies or thesauri, and may have broader terms, narrower terms, synonyms, and related terms. A record can include multiple Schlagwörter to cover different aspects of the content. Authority control ensures consistency: the same concept is always represented by the same term, and variant spellings or forms point to the preferred form.

Indexing process: trained indexers assign Schlagwörter based on the content. They consult vocabularies, library catalogs, and reference works to ensure consistency. In modern catalogs, subject headings appear in machine-readable form within MARC, BIBFRAME, or similar metadata and drive both discovery and faceted navigation.

History and use: Schlagwortkatalogs originated in traditional printed library catalogs as a counterpart to author- or title-based records. With the transition to online catalogs, Schlagwort indexing became integrated into metadata practices worldwide. In German-speaking libraries, Schlagwörter are used within the broader authority-control framework, often alongside authority files such as the Gemeinsame Normdatei (GND) and national vocabulary standards.

Contemporary relevance: Although search engines and full-text indexing provide keyword search, Schlagwortkatalog concepts remain essential for precise retrieval, cross-language access, and systematic browsing in library catalogs. Limitations include reliance on professional indexing, potential vocabulary gaps, and evolving vocabularies.