Introduction

Notwithstanding the many provisions and devices for the synthesis of numbers in the DDC, it is still often impossible to provide a class number covering all facets and aspects of a document. Take, for example, the title Cataloging in Academic Libraries. For this complex subject, class numbers exist separately for Cataloguing (025.3) and Academic libraries (027.7), yet these cannot be integrated through notation. One must be chosen. Similarly, a book on homeopathic medicine for heart disease will have to be placed either among Homeopathy (615.532) or Heart diseases (616.12). There is no provision to provide a class number covering both aspects. Furthermore, there may be books on composite subjects such as ‘libraries and museums management’, ‘introduction to physics and chemistry’, or ‘rudiments of electricity, electronics and magnetism’. Of these titles the class number can indicate no more than one subject. Why is this?

First of all, it should be remembered that any library classification, however synthetic, versatile and minute, cannot fully translate the subject of the document into notational symbols. The DDC has always been put forward as a system to group similar subjects, not one to individualize any bibliographic item by the class number alone. That is left to the call number (Satija, 2020). In fact no library classification can do this, notwithstanding the claims of stalwarts like S. R. Ranganathan, who projected classification as translation (Ranganathan, 1967). There cannot be a faithful translation of the subject of the document into notation. At best it is mere representation of the subject summary or dominant theme of the work. What then do we do in such cases? Which aspect of a subject do we represent and which do we ignore or suppress in the class number? This will depend upon the following:

• • the author's intention and emphasis (which are sacrosanct)

• • the local situation in the library (strong and weak areas in collection)

• • library policy regarding classification (broad vs close classification)

• • library policy regarding cataloging and indexing (cross references, number of subject headings);

• • the rules and instructions for this purpose in the Manual and notes and guidance in Merrill's Code (1939).