Probably no aspect of librarianship presents such variations of practice in individual libraries as does the provision of subject catalogues. The author catalogue, which tells the user whether a given work of which he knows the author and title is in the library, must necessarily take a similar form everywhere, and such variations as do exist in the treatment of certain types of heading—that of academies is a case in point—are quickly assimilated by the reader as he moves from library to library. The same cannot be said of the catalogue which tells the user what works are to be found in the library on a given topic. In the Anglo‐Saxon countries subject catalogues may be arranged, if indeed they exist at all, according to a variety of systems, and even where one of the accepted classification schemes or lists of subject headings is used the local modifications are often legion. Many university and research libraries find that no existing scheme offers an arrangement of the whole field of knowledge which reflects the approach to which their readers are accustomed; and certainly no ready‐made scheme is entirely suitable for a university library in the United Kingdom, although many libraries do attempt to provide a useful arrangement both of the books on the shelves and of the entries in the subject catalogue by adapting Dewey, the Brussels decimal classification, or the Library of Congress classification. Bliss, when his full scheme has been published, will probably be found to provide the arrangement most suitable for use in academic libraries, but even his admirable classification fails to provide a scheme which can be identified at all points with the approach which is required in a library which serves first and foremost the teaching of a university.