A practical approach to the reformed IPC

In a global collaborative effort, the Version 8 International Patent Classification Codes (IPC-8) have been applied to patent documents published prior to 2006 (backfile). This unprecedented effort employed multiple techniques, including use of earlier IPC versions, use of ECLA codes, and propagation of codes from one document to another within Inpadoc patent families. The result is that most records bear a relatively high number of codes, and family members from different authorities are coded relatively uniformly, at least at present. It is also notable that patent documents are not easily differentiated based on selective use of inventive codes because the vast majority of codes have been designated as inventive even where they cover subject matter that would be likely to figure as additional information in a substantial number of cases. Creating high precision search strategies relying on codes may be helped by requiring 2 or more codes to be present on individual documents or families. Sample searches presented are exemplary, and search strategies must be tested individually for optimizing searching in each subject matter area. Whether the reclassification effects and the propensity to make most codes "inventive" makes the IPC more akin to an indexing system is a question only time will answer. (C) 2009 Elsevier Ltd. All rights reserved.