Descriptors

Descriptors are controlled vocabulary terms that describe the subject matter of the source document. Descriptors include subject terms, personal names, and geographic locations. Every descriptor is assigned a unique code; you can search for the descriptor terms or codes.

Since April 1986, descriptors have been taken from the Thesaurus of Linguistic Indexing Terms. Prior to 1986, descriptors were taken from an Authority File of terms, which consisted of root words with a variety of suffixes, such as ethic, ethics, ethically, etc.

Some terms changed as a result of this transition. As a result, you may need to search for both the old and new terms for comprehensive retrieval. For example, the Authority File term "bigotry" was replaced by the Thesaurus term "prejudice", so you should search for (bigotry or prejudice) in de to retrieve all relevant records.

Some terms did not change from the Authority File to the Thesaurus, but the corresponding codes did change. (Authority File codes consist of six digits; thesaurus codes consist of the letter D followed by six digits.) As a result, you can search for one term or two codes to retrieve all relevant records. For example, the Authority File and Thesaurus both use the term "gerontology", but the code changed from 193600 to D326700. You can search for gerontology in de or (193600 or d326700) in de to retrieve all relevant records.

Descriptors are contained in the All Descriptors (DE) field. In addition, in records indexed in 1996 or later, descriptors are separated into the Major Descriptors and Descriptor Codes (DEM) and Descriptors and Descriptor Codes (DES) fields.