Three methods of indexing orthopaedic surgery patients have been presented together with some of the problems. The small file is discussed in more detail since it should be of more general interest. The other methods are mentioned principally to demonstrate more clearly the reasons why certain types of codes have specific advantages in special situations. No system is better than the individuals operating it. A cumbersome method would be more effective in the hands of a dedicated person than a well-designed system operated casually by the uninterested. Active interest and participation by the persons working with the cases is needed for success. It is hoped that some of our mistakes may be avoided by prospective indexers reading this article.