Scope notes are provided when needed to ensure cinsistency of subject usage by specifying the range of subject matter to which a heading is applied in the library's catalogs, by drawing necessary distinctions between related headings, or by statin g which of several meanings of a term is the one to which its use in the library's catalog is limited:

References: The Relationship Between Terms

USE References

USE references are made from an unauthorized or non-preferred term to an authorized or preferred term. Under the heading referred to, the code UF (used for) precedes the term not unsed. The codes USE and UF function as reciprocals:

USE references are made from synonyms, variant spellings, variant forms of expression, alternative constructions of headings, and older forms of headings. Headings consisting of more than one word frequently have USE/UF references from the words not chosen as the entry element:

Cross References

Subject headings are linked to other subject headings through cross references now expressed as Broader Terms (BT) and Narrower Terms (NT):

General References

A general reference is a reference made not to specific individual headings but to an entire group of headings. These general "see also" references use the code SA:

Subdivision Practice

Main headings may be subdivided by four kinds of subdivisions: TOPICAL; FORM; CHRONOLOGICAL; AND GEOGRAPHIC.

Topical Subdivisions

Topical subdivisions are used under main headings or other subdivisions to limit the concept expressed by the heading to a special subtopic:

Form Subdivisions

Form subdivisions are used to indicate the form in which the material on a subject is organized and presented (e.g. Congresses, dictionaries, periodicals). Form subdivisions represent what a work is, rather t han what it is about, and as such, are added as the last element to any heading, after main heading or subdivision:

Geographic Subdivisions

Subdivisions and subject headings that may be subdivided by the name of a country or other political entity, region, or geographic feature are identified in the list by the designation (May Subd Geog) fo llowing the heading and preceding the class number, if any. The designation (Not Subd Geog) after a subject heading or subdivision indicates that a decision has been made not to divide a particular heading by geographic location:

When the geographic entity is the name of a country or is larger than a single country, the established name is placed immediately after the heading or subdivision that has the code (May Subd Geog):

If a heading contains both a geographic subdivision and topical or form subdivision, the location of the geographic subdivision depends on which elements can be subdivided by place:

Filing Arrangement

Basically, the arrangement is word by word. A word is defined as consisting of one or more letters or numbers set off by spaces or marks of significant punctuation, such as the hyphen. Abbreviations, acronyms, and init ials separated by punctuation are filed as separate words at the beginning of their alphabetic group. Modified letters, with diacritics such as the umlaut, are treated like their plain equivalents in the English alphabet. Numbers that are expressed in d igits, both arabic and roman, precede alphabetic characters and are arranged in increasing numeric progression. Thus, it may be necessary to look under more than one possible form to find a heading, i.e. under numeric or alphabetic version. The shortest period is filed first in numeric progression:

Inverted headings file ahead of headings with parenthetical qualification:

In any subject heading, subordinate elements that follow a dash are grouped in the following order: