The miscellaneous folder should not be allowed to become too full. When a sufficient number of letters are accumulated with a firm or individual, or whenever the nature of the correspondence indicates that it is likely to become permanent, it should be transferred to a separate folder. _Geographical Indexing._ When for any reason it is desirable to have correspondence arranged according to territory, the geographical system of indexing is used to excellent advantage. The plan is exactly like alphabetical indexing, with the exception that the files are divided according to territory. First, the files are divided by states by means of state guides--indexes printed with the names of the states. A very large concern may require guides for all states, while a smaller business will use only three or four such divisions. Or a concern doing business in a half-dozen states may find it advisable to arrange the correspondence from but two of them territorially, indexing the balance alphabetically. The correspondence from a single state may require two or more drawers; or one drawer may accommodate that from several states. [Illustration: Fig. 18. Tab Folders. Miscellaneous Folders in front. _Library Bureau_] To subdivide the states, guide cards printed with the names of the towns are used. These are arranged alphabetically between the state guides. Correspondence folders are filed back of the town guides in alphabetical sequence. If there is a large number of correspondents in one town, the folders are subdivided with a set of alphabetical guides. The geographical method of indexing is shown in Fig. 19. [Illustration: Fig. 19. Geographical-Alphabetical Filing with Guides for States and Towns. _Library Bureau_] When the correspondence in a state is scattered, with but few correspondents in each town, a set of alphabetical guides can be substituted for the town guides. In New York state, for instance, the letter _A_ would represent Albion, Attica, and other towns the names of which begin with that letter. If there is a large town--as Albany--in which there are a number of correspondents, a town guide should be inserted in its proper place in the alphabetical index. Then, if the correspondence from Albany is sufficient, it can be subdivided with alphabetical guides, but these should be of a different color than those representing the towns. The geographical index can be expanded to any limit by inserting additional town and alphabetical guides, wherever and whenever needed. [Illustration: ONE OF THE STENOGRAPHERS' ROOMS AT THE PLANT OF THE POSTUM CEREAL COMPANY, LTD., BATTLE CREEK, MICH.] [Illustration: Fig. 20. Subject Indexing and Cross-Reference Notice Memoranda on Index Cards _Library Bureau_] _Subject Index._ The subject index is used whenever the subject of the correspondence is more important than the name of the writer. Subject indexing may be used in connection with the regular correspondence.