For a library database to be searchable, it must have an underlying authority file: a controlled vocabulary of names or subjects. In the authority file, all existing forms of the name, word, or expression must be cross-referenced to the single authoritative form, and all records (already existing ones and all those newly added) must be entered under it. The following examples illustrate the importance of authority files:

• Spelling of names Consistency of form ensures that Antonio Mira de Amescua refers to the playwright regardless of the alternate ways his name may have appeared in print or manuscript:  Antonio Mirademescua, Antonio de Amesqua, or Antonio de Mezqua.
• Pseudonyms  Antonio Enríquez Gómez often published under his pseudonym Fernándo de Zárate. His proper name appears as the main entry in all library records.
• Use of initials  All form of initials of a name must refer to the full name of the individual, for example L. A. J. M. for Luis Moncín.
• Un-ambiguating names  As an example of a name that needs in un-ambiguating, the printer la viuda Joseph de Orga, her name appears as Antonia Gómez.

The authority files for names of Authors/Translators/Adaptors, as well as for Printers/Publishers/Booksellers created for our database, are in the drop-down menu under RESOURCES. The landing page of the Glossary, with its cross-references, serves as a de facto authority file for the accepted forms of words included within.

One of the difficulties in creating this database was that national libraries operate independently from one another other. The Library of Congress and the Biblioteca nacional de España each has its own authority file, that often, but not always correspond. The few times that there is a lack of agreement in the form of a name, we have opted to follow Library of Congress’s form to facilitate the work of librarians in the United States. Examples:

• Gerónimo Cáncer. Biblioteca nacional de España  uses Cáncer y Velasco, Jerónimo de, 1599?-1655, whereas the LC uses Cáncer, Gerónimo, -1665. Notice the J/G difference in the first name, the expanded surname in the BnE version, and the lack of a approximated birth date in the Library of Congress version.
• Francisco Leiva. The Library of Congress uses Leiva, Francisco de, 1630-1676 as the authorized heading, with cross references to longer form used by the Biblioteca nacional de España. The BnE uses the longer form Leiva Ramírez de Arellano, Francisco de, 1630-1676 with cross-references to the shorter form used by the Library of Congress.

see also: general note(s), National Union Catalog / NUC pre-1956, OCLC / WorldCat