Complaints to the European Patent Office (EPO) are dealt with by a central EPO department known as Directorate Quality Support (DQS), which is also solely responsible for drafting and sending the official EPO response to the complainant. The default position is that both the original complaint and the reply thereto issued by DQS on behalf of the EPO are not made public, but rather are kept in the non-public part of the file to which the complaint pertains. This default position was apparently established by a decision of the President of the EPO in 2007. On the face of it, this would not appear to be a particularly contentious position, and is possibly justified given that complaints could be prejudicial to the legitimate personal or economic interests of third parties. Presumably the EPO would rather not place itself in a position of being a public outlet for any such potentially prejudicial remarks.

However, when it comes to oppositions before the EPO, a potential conflict with the above position arises owing to the conditions set out in Article 101 EPC in conjunction with Rules 79 and 83 EPC which, in summary, mandate the EPO to notify all exchanges to all parties during opposition proceedings. This would appear to include the notification by the EPO to the patent proprietor, for example, of any exchanges between the EPO, including the DQS as part of the EPO, and the opponent.

Decision T 1691/15 of the EPO's Technical Board of Appeal relates to an appeal from a decision of the Opposition Division. The Board, in considering a number of other matters such as the patentability of the proprietor's granted European patent, seemingly by chance discovered  that during the opposition proceedings under appeal there had been a number of exchanges between the then opponent, their representative and DQS. These exchanges were placed by DQS in the non-public part of the file and were not notified to the patent proprietor – presumably under the influence of the above-mentioned decision of the President regarding handling of complaints.

In its decision, the Board decided that the above-mentioned exchanges between the then-opponent and DQS should have been sent promptly to the patent proprietor by the Opposition Division, especially since they related to file-specific issues and were not ostensibly prejudicial to the legitimate personal or economic interests of third parties.

The Board has therefore provided some clarity that the conditions set out in Articles 101 EPC and Rules 79 and 83 EPC in respect of opposition proceedings should, by default, take precedence over the decision of the President in respect of complaints handled through DQS. In other words, the President's previous decision that complaints be kept non-public by default, should instead be an exceptional position. The Board also stated that it does not routinely perform a review of the entire file (public and private) to check whether there are any non-public documents which should be made public.

Going forward it may become routine practice for the Opposition Division or Board of Appeal to check the non-public part of the file for any correspondence that should be distributed to all parties. It is not yet clear if DQS will do this of its own volition.

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