In many western countries, modern and sophisticated forms of library catalogue are slowly replacing the card catalogue.
Some of these forms are:
• Visible index form
• Microform catalogue
• Machine-readable catalogue
1) Visible Index Form
This form of catalogue is extensively used in libraries attached to business and industrial houses. In Indian libraries, however, its use is limited. Visible index catalogue consists of strips mounted on a frame or cards held flat, hinged and with edge of each card protruding so as to make the heading visible. The cards are usually of the size 12.5 x 20 cm.; the card is inserted into a hinged kraft pocket, exposing the top portion. These pockets are held in a specially prepared steel cabinet. Such steel cabinets are available in India under the trade name Kardex. Generally, Kardex is used in Indian libraries for maintaining records pertaining to current periodicals.
There are variations of this type of commercially available equipment and are known by different trade names such as Chaindex and Stripdex. Except Kardex, which is somewhat popular, the other two types are used in a few Indian libraries. Kardex is not usually recommended for library catalogues but useful for current periodical catalogues.