1. Stands in place of terms used in the scheme of classification, so that whenever the term is to be represented it may be represented by a class mark only.
- The terms Mathematics, Chemistry, & Physics are refereed to by the notation (In DDC) 510, 530and 540 respectively
2. Shows the sequence of schedules and subordination of of subjects. That means it not only stands in place of terms but also acts as a guide to locate the position of them in the schedules.
Let,s take some terms used in DDC. The terms Mathematics, Astronomy, and Physics do not convey any one of there places in the schedules, but anyone can easily understand when we say:
- 510- Mathematics.
- 520- Astronomy.
- 530- physics.
3. Search to connect alphabetical order or index with the systematic order of schedules. That means consulting the number attach to the index entry, one can easily find out the place of subject in the classification schedules.
4. search to connect the catalogue with the shelves. The symbol written in the spine of the book are also written on the cards of the individuals books, hence by consulting the catalogue one can find out the exact location of a book or books on the shelves.
5. Maintenance systematic order on the shelves. The arrangement of books on the shelves should follow the systematic order shown on the classification scheme.
- i.e. main class past, then division, sub-division and so on.