Citing prior art in European patent applications

The IPKat has noticed a recent decision of an EPO Board of Appeal that relates to the question of whether it is necessary, rather than merely preferable, for a European patent application to mention relevant prior art known at the time of filing. The issue relates to Rule 42(1)(b), which states that the description shall "indicate the background art which, as far as is known to the applicant, can be regarded as useful to understand the invention, draw up the European search report and examine the European patent application, and, preferably, cite the documents reflecting such art".

Patent attorneys will be well aware that not mentioning relevant prior art known at the time of filing cannot of itself make a European application or patent invalid. The examiners for application 06024212.0, however, apparently thought differently, contrary to long-standing EPO practice. From a rather strained interpretation of the German version of the relevant rule, the examining division's view was that not including a reference to relevant prior art known to the applicant at the time of filing would make the application void ab initio. The application was refused as a result. The applicant, Samsung Electronics, unsurprisingly appealed.

In the resulting decision T 2321/08, the Board considered that the examining division had got it completely wrong. Rule 42(1)(b) did not put any stringent obligation on the applicant to cite relevant documents known at the time of filing, and failure to do so was in any case correctable after filing by making appropriate amendments. There was no reason to depart from the long-standing EPO practice of allowing amendments to be made to the description to cite relevant documents.

The IPKat wonders what on Earth the examining division in this case were thinking of, but is very glad that the Board reached the decision they did, not least because the consequences of the decision going the other way would have been very bad indeed. The well-known consequences in the US of not citing relevant documents are bad enough, but following the examining division's reasoning in this case would inevitably result in many currently pending European applications and granted patents becoming invalid without any hope of recovery. Following the decisions in G 1/05 and G 1/06, the IPKat finds it surprising that an examining division could even contemplate such a draconian interpretation of the rules.