Index is simply a list arranged alphabetically showing the required reference. An index to file may be set out in the form of a bound or loose leaf book whereas a separate page or group of pages is allotted to every letter of the alphabet, the field no. being entered against each name. Thus indexing is a system through which the location of the records may be found easily. It may be placed near to the records or may be kept apart from the records or the records themselves may be so arranged as to be self indexing eg . 1 index of a book (apart from the records) and 2. Telephone directory (self- indexing).
VERTICAL CARD INDEX
There are number of card in it and each card deals with one item of the index. On the top edge of the card, reference heading is written. On the remaining part of the card, the location of the item is written, where the self- indexing system is in use, the remaining part of the card contains the record itself. These cards are arranged vertically in a drawer or tray in such a way that they can be used very conveniently for reference to make the function or finding the reference more easily, tabbed guide cards may be inserted at required intervals.
It is consisted of frame into which strips of shout paper or card can be fitted in any required order and subsequently withdrawn and rearranged whenever changes are to be made. Each strip is devoted on one item of not more than two or three lines. Frames can be made up in various forms to suit different purposes; they can be fixed to the wall made up in book form or where a large number is necessary arranged on a rotary stand which is easily turned to give reference to any desired portion of the index.
VISIBLE CARD INDEX
This is an index which offers the ready visibility of the strip index and also the additional record space provided by the vertical card index. It consists of series of cards, arranged so as to overlap leaving a strip of each card exposed. This exposed edge is used for the reference heading, the remaining part of the card is readily available for record purpose. The trays in which these cards are kept are fitted with devices which enable the cards to be held in position and yet permit individual cards to be written upon withdrawn replaced or rearranged as may bar required. The trays of cards are usually kept in cabinet but as in the case of the strip index frames can be arranged in book form when they make an easily portable record.
Overlapping visible index records can also be kept in book form. A viable book consist of a loose leaf binder in which paper pages are arranged in a similar formation the cards in visible card index.
This is a form of vertical card index in which the cards are arranged about the circumference of wheel set in a cabinet or desk. Thousand of such cards can be attached to one wheel and as many as six wheels set up within the reach of one clerk seated at his desk.
STAGGED CARD INDEX
This is an arrangement of the vertical card index which has been developed to give easier reference to headings. Cards are arranged in groups and overlapped so that the reference headings on the cutaway concern of a whole group can be seen at once. This system of indexing is sometimes applied to ledger cards to facilitate the extraction of accounts for posting.
The cards are punched with holes along one or more edge, each hole represents a classification or figure in code number. Written information is recorded by hand or typewriting in the centre of the card. The information in term of which it is required to deselected or sort can be recorded along the edge of card by cutting the appropriate holes into slots. Once they have been prepared the card may be filed in trays in any order. To select the card for a particular classification batch of several hundred cards is removed from the tray and a long needle is passed through the holes representing the class required. When the needle is lifted the cards which have been slotted at these holes fall out so separate themselves from the remainder.