Markush structure searching over the years

Abstract

The indexing and retrieval of Markush structures has always been among the most problematic aspects of patent information and the most expensive. Indexing advanced from the simple classification systems of the 1950s to proprietary fragmentation systems, which were followed in the 1980s by topological systems. The cost of access to the latest indexing systems has varied widely over the years. In spite of improvements in indexing and less restrictive access conditions, comprehensive Markush structure searches remain the sole province of well financed organizations.