Nature of Entries to be Filed 

We have noted that catalogue entries are either word entries or notational entries. In a dictionary catalogue they are word entries. In a classified catalogue they are both word entries and entries under Class Number or Call Number notation. Ranganathan's Classified Catalogue consists of two parts-alphabetical and classified. The alphabetical part is the word entry part and the classified part is the notation entry part. 

Even in the alphabetical part of a classified catalogue or in a dictionary catalogue, sometimes, we come across numbers or symbols as entry element, For example, the name of the author may be given in symbols like. 

7 0 7 

etc., or the title of the work may not be in words but may be in numerals or symbols 

Eg.  100 Most Important People 

Y2K Problem 

Further, the shelf-list of a library is generally filed in the sequence in which the books are arranged on the shelves according to their call number Therefore, it is also in classified order, Filing of catalogue entries would therefore mean filing entries in a 

1. Shelf list; 
2. Classified Catalogue; and 
3. Dictionary Catalogue. 

Filing of word entries is known as 'Alphabetization' and filing of numerical and/or symbol entries is known as classified arrangement.