"The ULAN is a structured vocabulary currently containing around 293,000 names and other information about artists. Names in ULAN may include given names, pseudonyms, variant spellings, names in multiple languages, and names that have changed over time (e.g., married names). Among these names, one is flagged as the preferred name. Although it is displayed as a list, ULAN is structured as a thesaurus, compliant with ISO and NISO standards for thesaurus construction; it contains hierarchical, equivalence, and associative relationships. The focus of each ULAN record is an artist. Currently there are around 120,000 artists in the ULAN. In the database, each artist record (also called a subject in this manual) is identified by a unique numeric ID. Linked to each artist record are names, related artists, sources for the data, and notes. The temporal coverage of the ULAN ranges from Antiquity to the present and the scope is global. Although originally intended only for use by Getty projects, the broader art information community outside the Getty expressed a need to use ULAN for cataloging and retrieval. The Getty thus distributed ULAN for broader use according to the tenets previously established for the construction and maintenance of the AAT: Its scope includes names needed to catalog and retrieve information about the visual arts and architecture; it is based on terminology that is current, warranted for use by authoritative literary sources, and validated by use in the scholarly art and architectural history community; and it is compiled and edited in response to the needs of the user community. Originally constructed as a simple alphabetized "union list" of clustered artist names and biographies, in order to make it consistent with the AAT and TGN, in the late 1990s ULAN was brought into compliance with national and international standards for thesaurus construction. Its scope was broadened to include corporate bodies such as architectural firms and repositories of art, which may have hierarchical levels."