Checking with the catalogue:

The individual classifier  who is allotted a  set of documents for processing will first  check  each item in the set with the library catalogue. The purpose here is to know: 

a) Whether the document is a subsequent copy of an already processed item 

b) Whether it is a different edition clan already processed item 

c) Whether it is a new volume of an already processed multi-volumed set 

d) Whether it is totally a new document to be processed 

In the case of the first three categories, technical processing work is not required. The document in question is to be given the same class number with necessary changes in the book number. The information about these documents has only to be entered in the already existing catalogue entries. This is known as consolidating work. Here the classifier will have only to pull out the relevant cards from the catalogue, incorporate the information, and refile in the catalogue. The books are then prepared for use by writing the Call Number on the book, writing the Book Card and the Shelf-Card as in the case with other books. 

It is in the fourth category of documents that technical processing has to  be done. They are subjected to the following processes. 

Determining the Specific Subject:

The classifier's first task is to decide the specific subject of each document. For this, he needs to understand correctly the thought content of the document. For this purpose he cannot completely  rely on the title of the document since titles may be too broad, ambiguous, misleading or even fanciful. He should go beyond the title to the sub-title, if any, then to the foreword, preface or introduction, the table of contents, the information given on the book jacket, and even the text itself. If necessary, dictionaries or other reference books should be consulted. The postulational approach for subject  analysis/classification suggested by Ranganathan will be useful in determining the specific subject of the  document irrespective of the scheme used.