The or SWD (translated as ''Subject Headings Authority File'') is a
Controlled vocabularies provide a way to organize knowledge for subsequent retrieval. They are used in subject indexing Subject indexing is the act of describing or classifying a document
A document is a written
Writing is a medium of ... index term An index term, subject term, subject heading, descriptor, or keyword, in information retrieval
Information retrieval (IR) in computing
Computing is any goal-oriented activity requiring, benefiting from, or creating computing machinery. It inc ...
system used primarily for
subject indexing Subject indexing is the act of describing or classifying a document
A document is a written
Writing is a medium of human communication
Communication (from Latin ''communicare'', meaning "to share") is the act of developing Semantics, m ...
A library catalog (or library catalogue in British English) is a register of all bibliography, bibliographic items found in a library or group of libraries, such as a network of libraries at several locations. A catalog for a group of libra ...
s. The SWD is managed by the
German National Library
The German National Library (DNB; german: Deutsche Nationalbibliothek) is the central archival library and national bibliographic centre for the Federal Republic of Germany
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(DNB) in cooperation with various
A library is a collection of materials, books or media that are easily accessible for use and not just for display purposes. It is responsible for housing updated information in order to meet the user's needs on a daily basis. A library provi ...
networks. The inclusion of keywords in the SWD is defined by (RSWK) (English: Rules for the keyword catalogue). Similar authority systems
in other languages include the
Library of Congress Subject Headings The Library of Congress Subject Headings (LCSH) comprise a thesaurus
A thesaurus (plural ''thesauri'' or ''thesauruses'') or synonym dictionary is a reference work for finding synonyms and sometimes antonyms of words. They are often used by wri ...
(LCSH) and the (). Since April 2012 the SWD is part of the (GND) (English: Integrated Authority File).
The SWD has about 600,000 descriptor
s and 700,000 non-descriptors (
A synonym is a word, morpheme
A morpheme is the smallest meaningful lexical item in a language. A morpheme is not a word. The difference between a morpheme and a word is that a morpheme bound and free morphemes, sometimes does not stand alone ...
s and quasi-synonyms) as well as synonymous descriptor chains with references to a descriptor. Its growth rate is about 5.5% per year. About three-quarters of the descriptors refer to individual concepts (language identifier, person, entity, title, ethnography etc.) and a quarter are abstract concepts. Linking using hierarchical (about 115,000) and associative (26,000) relations is not very dense, so the SWD cannot be viewed as a
A thesaurus (plural ''thesauri'' or ''thesauruses'') or synonym dictionary is a reference work for finding synonyms and sometimes antonyms of words. They are often used by writers to help find the best word to express an idea:
Synonym diction ...
(as of mid-2003).
The terms in the SWD are also arranged in a separate
classification Classification is a process related to categorization
Categorization is the human ability and activity of recognizing shared features or similarities between the elements of the experience
Experience refers to conscious
, an English Paracels ...
with nearly 500 classes in 36 main groups.
The various terms are placed in a classification scheme and also contain references to sources, related terms, preferred term and to a lesser extent hierarchical links. But the SWD is probably not a complete thesaurus because of the low degree of linkage. The SWD is available online through the catalogue database ILTIS and is available for a fee as BIBLIODATA, together with the (PND) (English: Name Authority File) and the (GKD) (English: Corporate Bodies Authority File) on the standard data CD-ROM and the standard file TITAN. In both cases, the user interface of the SWD leaves much room for improvement. Instead of making SWD accessible as a user-friendly navigation tool, it assumes that users are familiar with SWD and its classification scheme and enter the appropriate descriptor in the correct form before running a search. Navigating the system or moving from one concept to another by means of hyperlinks is not possible. The strategy of the German Library to distribute authority records commercially makes the extended use of the SWD difficult, e.g. in other keyword systems.
For the exchange of authority records, there is a separate machine exchange format for libraries called MAB-SWD
. The head official of the Southwest German Library Network (SWB) offers online access (OSWD).
Faceted Application of Subject Terminology Faceted Application of Subject Terminology (FAST) is a general use controlled vocabulary
Controlled vocabularies provide a way to organize knowledge for subsequent retrieval. They are used in subject indexing Subject indexing is the act of descr ...
(FAST), a simplified syntax of LCSH
Canadian Subject Headings Canadian Subject Headings (CSH) is a list of subject headings in the English language, using controlled vocabulary, to access and express the topic content of documents on Canada and Canadian topics. Library and Archives Canada publishes and maintai ...
Searching the OSWD
about the SWD
* Rules for the Keyword Catalogue (RSWK) 3rd edition, Deutsches Bibliotheksinstitut, 1998
2012 disestablishments in Germany
Library cataloging and classification