Wikipedia:Authority control

Authority control is a method used to assign a unique identifier to each topic, which, like Wikipedia's own disambiguation process and redirects, is critical for subjects that either have the same name but refer to different topics, like differentiating between John Smith (professor) and John Smith (English poet), or have different names but refer to the same topic, like Mark Twain and Samuel Langhorne Clemens.

The Authority control template links Wikipedia articles (and user pages) to the corresponding entries in library catalogs of national libraries and other authority files all over the world. The entries typically correspond to people, book titles, and similar well-defined entities and are stored in Wikidata.

, the English Wikipedia has approximately 2,110,000 articles tagged with Authority control.

Linked catalogs
The template can display identifiers from many authority files: GND (German National Library and partner institutions), LCCN (Library of Congress), SELIBR (National Library of Sweden), VIAF (Virtual International Authority File by OCLC), ORCID (Open Researcher and Contributor ID), and more (30+ sources, see "local conf" list at Module:Authority control). Some authority files are themselves aggregators – for example, VIAF combines authority records from over 40 national libraries and other authority files like the Getty Union List of Artist Names.

Purpose
National libraries and other libraries, archives and collections use authority records to link works to specific persons who either were involved in the creation of these works or are the subjects of these works. Such works can be books, comic books, music albums, all kinds of videos (movies, documentaries, TV series), paintings, manuscripts and so on.

Direct benefits to readers are direct access to these linked works where available (e.g. finding a library holding a particular book on a topic).

Initially, en.wikipedia has used authority control data for biographical articles only. Authority files, however, are not restricted to information about people. Some files contain data about organizations, geographic names, work titles, or general subject terms or keywords.

By adding authority data to Wikipedia articles, software developers from both the Wikimedia and library communities will be able to create new tools to link and combine information from Wikipedia and databases and online catalogs that use these identifiers. Such tools may use the simple BEACON file format, pioneered by the German Wikipedia community, to connect external sources by dynamic links.

Position
As a metadata template, the Authority control template should be placed after the external links section and navigation templates.

Non-1:1 and non-exact matches
There are many cases where the topic in Wikipedia does not match the topic in the authority control system (see for example Category:Redirects from pseudonyms for examples of people with more than one name, or Category:Groups of people for examples of articles about multiple people). In these cases, the Authority control template should be put on the page (article or redirect) that most closely matches the topic in the authority control system. If necessary, create a new redirect to carry the template. Redirects are cheap.

ISNI
The ISNI (International Standard Name Identifier) is an identifier based on an ISO standard.

VIAF
The VIAF ID corresponding to the subject of the article can be found on viaf.org which combines authority records from many organizations worldwide into single datasets. Enter the person's name in the search field and find the corresponding dataset in the search results. The VIAF ID can be found underneath the name list.

If the entries for a particular person in the various authority records haven't been merged into a single VIAF dataset yet, use the VIAF ID that contains the subject's LCCN. Sooner or later VIAF will merge them into one dataset and redirect to this from old IDs.

LCCN
The Library of Congress Control Number can be found on various websites. The easiest way is via viaf.org (see above). Other options are the websites of Library of Congress Identities and Worldcat Identities.

Note that the LCCN has to be formatted in a special way so it can be used in the template: it consists of an alphabetic prefix ("n", "nr", "no", etc.), the year (two digits, four digits since 2001) and a 6-digit serial number. These parts must be separated by a "/" and leading zeros of the serial number must be removed.



GND (former PND)
GND records can also be found via viaf.org. They are marked with "DNB" (Deutsche Nationalbibliothek). The GND entries in the VIAF datasets are linked to the entries in the online catalogue of the German National Library. In the GND record, the identifier can be found in the field "Link zu diesem Datensatz" ("http://d-nb.info/gnd/170118215" means the GND number is 170118215). Note that only biographical records where the name field is labeled "Person" are valid GND records that can be used in this template. If the name field is labeled "Name", this particular record is not individualized, which means that the record can contain publications of various authors of the same name. Within VIAF, such non-individualized GND records are labelled as (undifferentiated).

Another method is to search directly on portal.dnb.de. You may restrict the search results by the links under the heading "Alle Normdaten" on the right. For authority data about persons, click "Personen".

SELIBR
The identifier used by the National Library of Sweden can also be found via viaf.org. The VIAF datasets containing such identifiers link to the authority records at libris.kb.se. Copy the number in the last part of that web address and paste it into the SELIBR parameter in the template.

ORCID
ORCID (Open Researcher and Contributor ID) is a nonproprietary alphanumeric code to uniquely identify scientific and other academic authors. Authors – including Wikipedia editors – may obtain an ORCID by signing up at orcid.org

See WP:ORCID for more.

MBA
The MusicBrainz Artist ID is an ID in the open music encyclopedia MusicBrainz. If you have the link to the artist on MusicBrainz, the ID is the last part of the URL.

Examples
Simply adding  will display all the authority control information associated with the article in Wikidata. Managing the information in Wikidata ensures that it is available to other languages and projects as well. For full details see.

Here are some examples:
 * Stephen King:


 * Albert Einstein:


 * Barack Obama: