Filing Classified Entries
By classified entries, we mean entries which hear notation; that is, Class Number and Call Number entries. A Subject Catalogue and an Alphabetico-Classed Catalogue also are known as Classified Catalogues. Ranganathan considers a Classified Catalogue as a "Catalogue in which some entries are number entries and some are word entries".
Filing of number entries will be easy when a simple scheme of Classification like Dewey Decimal Classification is used. The numerals and their sequential value is quite familiar to us. So the arrangement is simple.
For example when numbers like 030; 360; 130; 505; 330; 720; etc., are to be arranged we an-arrange them in the sequence
030
130
330
360
505
720
Similarly, when Class Numbers are based on pure notation using letter of alphabets like ABCD we can conveniently arrange them in a sequential order
AAC
AAH
AAL
ABC
ABG
ABK
ACD
ACM and so on
When both - alphabet letters and numerals are used in a mixed notation their arrangement needs some guidance as to whether letters should be taken first or numerals. If both capital letters and small letters are used and in addition both Arabic numerals and Roman numerals are also mixed up, then again some guiding principles of preference and sequence are needed. Filing becomes much more complicated when characters and symbols like - " " &; etc., appear as indication digits.