The link between science and technology represents a major strategic stake, so the relation between scientific bibliographic references and technical bibliographic references can be of very important documentary interest. To set up this link, International Patent Classification catchwords have been used as a switching language. A previous feasibility study had shown the possibilities of such a full automatic correspondence and its obvious inadequacies. We present here the most important modifications brought to this correspondence, in particular the consideration of multilingual indexes which allow to link several indexation fields with one of the most complete representation of patent classification. The major evolution of our project affects the correspondence mechanism which now generates a global reindexation of bibliographic reference with classification codes. We also discuss the concept of correspondence itself which must be interpreted as a simple presumption of the link. There are some consequences due to these developments: first, insofar as there is not an univocal relation, end users do not have to select switching keywords which generate concordances. They can directly use codes which symbolize the industrial property classification. Next, main documentary indicators do not seem to be adapted to measure the performance evaluation of this new field. It has the single role of suggesting trails that can be explored. Lastly, it seems that only end users should be able to supply a complete validation and we show that a documentary validation is not sufficient.