The patent information available on QUESTEL

The article describes the origin and development of the technical information organization. Telesystemes QUESTEL, the extent of its patent files, covering French and EPO patent documents and the EPO patent family file, the cooperation with Derwent Publications which enabled the World Patents Index (WPI) to be loaded on the QUESTEL mainframe, the possibility for statistical analysis of patents, the availability of chemical substructure searching and the development of Markush DARC software to enable, in the near future, handling of Markush formulae.