Editing Authority control (section)

==Authority records and files==
A customary way of enforcing authority control in a bibliographic catalog is to set up a separate index of authority records, which relates to and governs the headings used in the main catalog. This separate index is often referred to as an "authority file". It contains an indexable record of all decisions made by catalogers in a given library (or—as is increasingly the case—cataloging consortium), which catalogers consult when making, or revising, decisions about headings.  As a result, the records contain documentation about sources used to establish a particular preferred heading, and may contain information discovered while researching the heading which may be useful.<ref name =Calhoun />

While authority files provide information about a particular subject, their primary function is not to provide information but to organize it.<ref name="Calhoun">{{Cite conference | first = Karen | last = Calhoun | publisher = [[California Academy of Sciences]] | url = https://researcharchive.calacademy.org/research/informatics/taf/proceedings/Calhoun.html | title = A Bird's Eye View of Authority Control in Cataloging |book-title=Proceedings of the Taxonomic Authority Files Workshop |conference=Workshop on the Compilation, Maintenance, and Dissemination of Taxonomic Authority Files (TAF): a comparison of authority control in the library science and biodiversity information management communities |conference-url=https://researcharchive.calacademy.org/research/informatics/taf/index.html |date=June 22–23, 1998 |location=Washington, D.C. |access-date=25 November 2012}}</ref> They contain enough information to establish that a given author or title is unique, but that is all; irrelevant but interesting information is generally excluded.  Although practices vary internationally, authority records in the English-speaking world generally contain the following information:

* ''Headings'' show the preferred title chosen as the official and authorized version. It is important that the heading be unique; if there is a conflict with an identical heading, then one of the two will have to be chosen:
{{Blockquote |Since the headings function as access points, making sure that they are distinct and not in conflict with existing entries is important. For example, the English novelist William Collins (1824–89), whose works include the Moonstone and The Woman in White is better known as Wilkie Collins. Cataloguers {{sic}} have to decide which name the public would most likely look under, and whether to use a see also reference to link alternative forms of an individual's name.|Mason, M.K.|title=Purpose of authority work and files|source=http://www.moyak.com/papers/libraries-bibliographic-control.html}}
* ''Cross references'' are other forms of the name or title that might appear in the catalog and include:
#''see'' references are forms of the name or title that describe the subject but which have been passed over or ''deprecated'' in favor of the authorized heading form
#''see also'' references point to other forms of the name or title that are also authorized. These ''see also'' references generally point to earlier or later forms of a name or title.
* ''Statement(s) of justification'' is a brief account made by the cataloger about particular information sources used to determine both authorized and deprecated forms. Sometimes this means citing the title and publication date of the source, the location of the name or title on that source, and the form in which it appears on that source.

[[File:An example of an authority record.png|thumb|right|300px]]
For example, the Irish writer [[Brian O'Nolan]], who lived from 1911 to 1966, wrote under many [[pen name]]s such as Flann O'Brien and Myles na Gopaleen. Catalogers at the United States Library of Congress chose one form—"O'Brien, Flann, 1911–1966"—as the official heading.<ref>{{Cite web | url = http://authorities.loc.gov/ |website=Library of Congress | title = Authorities files }}; the original record has been abbreviated for clarity.</ref>  The example contains all three elements of a valid authority record: the first heading ''O'Brien, Flann, 1911–1966'' is the form of the name that the [[Library of Congress]] chose as authoritative. In theory, every record in the catalog that represents a work by this author should have this form of the name as its author heading. What follows immediately below the heading beginning with ''Na Gopaleen, Myles, 1911–1966'' are the ''see'' references. These forms of the author's name will appear in the catalog, but only as transcriptions and not as headings. If a user queries the catalog under one of these variant forms of the author's name, he or she would receive the response: "See O'Brien, Flann, 1911–1966." There is an additional spelling variant of the Gopaleen name: "Na gCopaleen, Myles, 1911–1966" has an extra ''C'' inserted because the author also employed the non-anglicized Irish spelling of his pen-name, in which the capitalized ''C'' shows the correct root word while the preceding ''g'' indicates its pronunciation in context. So if a library user comes across this spelling variant, he or she will be led to the same author regardless. ''See also'' references, which point from one authorized heading to another authorized heading, are exceedingly rare for personal name authority records, although they often appear in name authority records for corporate bodies. The final four entries in this record beginning with ''His At Swim-Two-Birds ... 1939.'' constitute the justification for this particular form of the name: it appeared in this form on the 1939 edition of the author's novel ''At Swim-Two-Birds'', whereas the author's other ''noms de plume'' appeared on later publications.
[[File:Sample Catalog Record.png|thumb|220px|Card catalog records such as this one used to be physical cards contained in long rectangular drawers in a library; today, generally, this information is stored in online databases.<ref name = "Calhoun" />]]
[[File:Sample Name Authority Record.png|thumb|220px|Authority control with "Kesey, Ken" as the chosen heading.<ref name = "Calhoun" />]]