The author and title catalog is distinguished from the author and catch-word catalog by the entry of anonymous titles under the first word rather than under the most significant word.
6b. Following a natural evolution, the systematic library catalog and the alphabetical classed catalog are practically extinct species, overwhelmed in the struggle for existence by the alphabetical subject catalog's quick and ready reference. This economy is, to be sure, effected for the average use, at a very great expense to the use of a good many readers who wish to consider all related aspects of a topic, but with the growing habit of classification of libraries, there is in fact a handy substitute, for these readers, in the classification, its index, and the shelf list. The alphabet subject catalog has thus become the recognized sole form of subject catalog for users in general.
7. The nature and origin of the alphabetical subject catalog is the same as that of the alphabetical encyclopedia, the alphabetical index to books and alphabetical index to a system of classification. Its rules and applications may, therefore, be guided by experience and practice in these three fields as well as direct experience in the alphabetical subject catalog.
8. Habit being a chief factor in quick reference, it is important that the name of the subject should be that of common usage. By this is not meant necessarily the use of the common people, but the form generally used in book indexes, encyclopaedias, and library classifications. It is greatly to be desired that all encyclopedias, classifications, indexes and alphabetical subject catalogs should use just the same terms—the same form among synonyms, the same practice as to singular or plural, adjectives or substantive entry.
9. At least the names of the subjects in the alphabetical subject catalog should be identical with those of the alphabetical index to the systematic catalog if there is any or the classification of its own library.
10. Whatever names are used must be clearly defined. This is the first principle of subject cataloging, whether the arrangement is alphabetical or systematic, that the subject word shall be so clearly defined that there is no mistaking what is to go under it. It is hard to lay too much stress on this matter. It is the Alpha and Omega of subject cataloging of every sort, besides which even uniform names and the question of arrangement are quite secondary.
11. In choosing the names for classes, the most specific should be used. This is a very important aid indeed to clear definition. The only objection is the splitting of kindred subjects—the same idea which leads to the alphabetical classed or systematic catalog.
Many cautions are issued warning against being too specific—some well founded, but the danger lies almost wholly in the other direction. There may be a limit but the principle is one of the clearest and most important in the whole matter and even the encyclopedias—even the Britannica itself—are getting further and further away from the old Britannica type.
12. The names of subjects so far as they are identical with author catalog entries should be determined by the same rules as in the author catalog. This is another important aid to uniform names which should be strictly insisted on.
13. The alphabetical subject catalog should have a classed index, as the classed catalog or the shelf list must have an alphabetical index. Note that the index to the new Britannica by its alphabetical index recognizes itself as an alphabetical classed encyclopedia rather than an alphabetical subject encyclopedia. Note also that it has the systematic index—the idea which in the end must be applied to every alphabetical subject catalog and which will be fully served automatically if the names of the classification index are identical with the subject headings and the class number attached to each of the subject catalog headings.