This preface is intended to outline catalog construction principles in
everyday language, and to show how these principles are reflected in the
steps involved in the job of cataloging a book.
It is important to note that this code is not concerned with the catalog in the broadest possible sense but only with its "formal" aspects (titles, names, imprints, etc.) as opposed to the "subject" aspects (topics, categories, shelving classes). Both are mostly combined into one catalog (formerly called a "dictionary catalog"), but the rules for both aspects have not been combined. Two libraries may, in fact, use the same formal rules but different rules for subject terms. The Anglo-American Cataloguing Rules, for example, cover the first aspect only, they do not even mention the second.
Principles for Formal Cataloging
The catalog of a library should provide access to the library’s collection of books and other materials in accordance with formal criteria.This means:
1. It should make the available materials reliably findable. The user must be able to find with certainty each object in the collection according to specified characteristics that are normally in or on the object. This also serves to ascertain that an object is not in the collection.
2. It should differentiate among the dissimilar. Each object should be described succinctly but in sufficient detail that it can be distinguished from other objects in the collection.
3. It should relate and display together objects that belong together. The catalog, on the other hand, must also bring together objects that belong together; that is, it must show the user that they are related, especially, for example, the works of an author, the available editions or versions of a work, or the component parts of a multipart work or a series.
4. It should clearly display that which is found. If there are several or more entries in the catalog that meet the search criteria, the catalog should present them in a clear manner that facilitates selection by the user.
5. It should make the selected object accessible. The user is interested in the quickest way of accessing the selected object.Card catalogs display only the location and call number; online catalogs, on the other hand, can lead directly from the record to use: they can facilitate the ordering or reserving of an item, or link one directly to the document online.