A.L.A. List of Subject Headings for use in Dictionary Catalogues. 3rd ed., by M. J. Briggs, 1911. Mann, M. Subject Headings for use in Dictionary Catalogues of Juvenile Books, 1916. A.L.A. Library of Congress. Preliminary List of Subject Sub-divisions, 1910. Edited by J. C. M. Hanson. =296. Card Catalogues:= Carnegie Library of Pittsburgh. Rules for Filing Cards in the Dictionary Catalogues, 1917. Sayers and Stewart. The Card Catalogue, 1913. Grafton. =297. Sheaf Catalogues:= Stewart, J. D. The Sheaf Catalogue, 1909. Grafton. =298. Co-operative Cataloguing:= Jahr, T., and Strohm, A. J. Bibliography of Co-operative Cataloguing and the Printing of Catalogue Cards: with References to International Bibliography and the Universal Catalogue, 1850-1902. 1903. =299. Cataloguer’s Reference Books:= New York State Library. Selections of Cataloguer’s Reference Books in New York State Library, 1903. See also Brown’s Library Classification and Cataloguing and Stewart’s Sheaf Catalogue. For articles, see Cannons: I, Cataloguing. CHAPTER XX FILING AND INDEXING =300. General.=--Although the library invented the card index, it may be confessed that in this country the library has not yet realized the possibilities of its own invention, even if it is convinced of its complete desirability. We make no question, however, of the fact that such methods as card-indexing and its derivative, vertical filing, become more necessary every day if the librarian is to handle with any degree of success the multiplicity of documents, prints, papers and other disparate matter which form so important a part of the stock of a really living library. Since the publication of the second edition of this MANUAL the whole matter has made such advances that a complete reversal of many of the statements and recommendations made in it is necessary. The general indexing and filing problems before the librarian are these: 1. Borrowers’ register. 2. Stationery and supplies register. 3. Correspondence filing and indexing. 4. Indexing of minutes. 5. The filing of clippings. 6. The filing of broadsides, prints, photographs, maps, lantern slides, negatives. 7. The filing of deeds. 8. The filing of pamphlets. As the index is the key to the filing system, we will treat of filing methods first. [Illustration: FIG. 114.--Folder for Vertical File.]