=Cross-Indexing the Chronological File.= One of the disadvantages of the tickler or chronological index, described above, for a follow-up is the difficulty of locating a card, when the date under which it is filed is unknown. A letter may be written on June 10, and the card filed ahead to June 25; on June 16 a reply may be received which makes it necessary to find the follow-up card, but to do this it is necessary to look through all of the cards filed between June 16 and June 25. If the card is not found, the chances are that on the 25th a regular follow-up form letter, which will make the system appear ridiculous, will be sent. [Illustration: Fig. 25. Follow-up Card with Alphabetical Tab] To so file the cards that any one can be found by name, without interference with the automatic features of the follow-up system, is an important consideration. This can be accomplished by the use of a card like the one shown in Fig. 25. It will be noted that this card bears a small tab or projection, on which is printed the letter _B_. These tabs are cut 1/20 of the width of the card and are in twenty positions across the card. This allows for twenty subdivisions of the alphabet, the _A_ tab being in the first position, _B_ in the second, etc. In filling in a card, one bearing the letter corresponding with the first letter in the name of the correspondent is selected--a _B_ card for Brown, an _S_ card for Smith. Now since _B_ is always printed on a tab in the second position, and this tab is always the same distance from the end of the card, when the cards are filed, all _B_ tabs will be in a straight line from front to back of the drawer. No matter under what date it is filed, if Brown's card is wanted it will be found by looking through the row of _B_ tabs in the second position from the left. Regardless of the number, all tabs printed with the same letter are found in one row, making it possible to file cards by date and cross-index by name. [Illustration: Fig. 26. Follow-up Card with Movable Tab to Show Dates] =Cross-Indexing the Alphabetical File=. An improvement over the cross-index of the tickler, described above, is the method of cross-indexing an alphabetical file in a manner to insure a follow-up on a specified date. A card without tabs, as shown in Fig. 26, is used. Across the top of the card is printed a series of numbers representing the days of the month. This may include all of the numbers, from 1 to 31, or the month may be divided into five day periods. In connection with this card a metal tab, which can be attached at will, is used. One of these tabs is placed over the number which represents the date on which it is to be followed up. The card is then filed, indexed by name. [Illustration: THE SALES DEPARTMENT IN THE NEW YORK OFFICES OF J. WALTER THOMPSON COMPANY]