Important Abbreviations 2

BT: This stands for broader topic(s). These are other valid subject terms that are broader in scope than the term they are listed under. These broader terms are listed to help the user find general subjects that include the specified topic. In the example below, the subheading "Siege, 1775-1776" leads to a broader topic of "Sieges--Massachusetts."

— History
               [F73]
    — — Colonial period, ca. 1600-1775
    — — Siege, 1775-1776
                   BT Sieges—Massachusetts
    — — Revolution, 1775-1783
                  NT Boston Port Bill, 1774
                        Boston Tea Party, 1773

NT: This stands for narrower topics. The valid subject terms listed after NT are more specific aspects of the term they are listed under, and may help the user find more in-depth information related to this topic. Narrower topics for Boston (Mass.)--History--Revolution, 1775-1783 would be Boston Port Bill, 1774 and Boston Tea Party, 1773. Because neither of these headings is preceded by a dash, they are considered independent subject headings and do not have to be preceded by Boston (Mass.).

Botanical gardens (May subd Geog)
         [QK71-QK73]
     UF Botanic gardens
     BT Gardens
           Research institutes
     RT Arboretums
     SA names of individual botanical gardens

RT: This stands for related topic(s). The valid subject terms listed after RT are somehow related to the term they are listed under. Under older cataloging rules, these are referred to as ‘see also’ references. In the above example, "Arboretums" is a related topic to "Botanical gardens." See also references can be made to the names of particular botanical gardens.

These definitions are important to understand, as they form the bulk of the information in the subject heading list. Knowing the meaning of the various terms and abbreviations helps the user to more readily understand the information included with each subject heading. In particular, the scope notes are very important. For example, for many subject headings the singular and plural form of a word may have different meanings when looking at how the word is used in a cataloging record. The scope notes under various headings help to explain how these interpretations are made. Notes also help to explain whether the subject term or geographic area name will come first in an entry if there is a need to indicate a geographic area in a heading. Scope notes may also be included under subdivisions of a topic, to further explain the use of that subdivision.