b'Maintaining a Catalog / Revising Subject Headingsdoes not aim at completeness and must be expanded. Even where there is no general reference,narrower terms for types of things and examples and instances of things must be added as needed.At times it is nearly impossible to determine what broader concept or category a new subject mightbe included under. This should not deter the cataloger from establishing any heading that is needed.Take, for example, the case of a book on thumb sucking, a common phenomenon among smallchildren. The nearest terms in the List might be Child psychology, Child rearing, or Humanbehavior, but they are none too near. Nowhere is there a general reference instructing the catalogerto add headings for common childhood phenomena, and still the only appropriate heading for thebook would be Thumb sucking. Here the intrepid cataloger, thinking how useless the headingsChild psychology, Child rearing, or Human behavior would be on such a book, adds the headingThumb sucking to the List and enters the book into the catalog under that heading.There are resources that a cataloger can turn to for help in establishing subject headings that are notin the List. Other available databases and catalogs in which books are listed by subject can alwaysbe consulted, such as the Web site of any large library whose catalog is online. Periodical indexes,such as ReadersGuide to Periodical Literature or Applied Science & Technology Index,areespecially helpful in establishing headings for current events and very new topics and trends and fortechnical headings. The index and the schedules of the Dewey Decimal Classification are a usefulsource of subject terminology as well as a way of seeing a topic in its relation to other topics. TheLibrary of Congress issues lists of new subject headings in Library of Congress Subject HeadingsWeekly Lists on its Web site and includes new subject headings of current interest in its quarterlyCataloging Service Bulletin. Library of Congress cataloging information, including subjectheadings, emanating from its Cataloging in Publication (CIP) program, is available in various onlinedatabases and is also printed on the title page verso of many books.REVISING SUBJECT HEADINGSBecause the English language does not stand still, neither do subject headings. It would beimpossible today for a catalog to maintain the headings Negroes or Dinosauria, since common usagehas relegated these terms to history. The prevailing thinking about the form of subject headings alsochanges, and as a result whole groups of headings need to be revised. All the inverted headings inthe Sears List, for example, were eventually revised to the uninverted form, such as Healthinsurance for Insurance, Health. With each new edition of the Sears List a library should consultthe List of Canceled and Replacement Headings in the front of the volume and revise its catalogaccordingly. Any headings created locally based on the pattern set by a Sears heading, and stringsconsisting of a Sears heading and a subdivision, must also be revised if that heading is revised inSears. If, for example, a library had added the headings Insurance, Title and Insurance, Health Law and legislation, those headings would need to be revised to Title insurance and HealthinsuranceLaw and legislation.A-44'