A BOOK‐NOTATION FOR SPECIAL LIBRARIES Available to Purchase

No classification will last for ever, and it will rarely last half a century without becoming obsolete. Therefore the main quality that is required from a classification is susceptibility to modifications even in its foundation. Generally there would be no difficulty in revising a classification by the insertion of new main classes and the addition of new subdivisions, if this were not prevented by the notation. When using the common notations, e.g. that of the Decimal Classification, it is impossible to insert anywhere an indefinite number of new parallel sections, either in the main classes or in the subdivisions.