Over the past 40 years, the Boards of Appeal have developed a substantial body of case law: during this time, we have dealt with more than 46 000 cases and issued over 35 000 decisions. In the same period, the Enlarged Board of Appeal has handed down more than 100 decisions and opinions under Article 112 EPC, in order to clarify legal points of fundamental importance and ensure a uniform application of the law.

The present ninth edition of the "Case Law of the Boards of Appeal of the European Patent Office" provides a comprehensive overview of this case law. It contains summaries of or references to almost 7 000 decisions which were issued in writing in the period up to the end of 2018. Also included are a number of important decisions rendered at the beginning of 2019, as well as the questions of law referred to the Enlarged Board of Appeal under Article 112 EPC in cases G 1/19, G 2/19 and G 3/19.

As in previous editions, the decisions are ordered according to topic, although some chapters have been re-arranged to reflect developments in the case law or to allow relevant decisions or topics to be located more easily. Readers should also note that, between editions of the book, regular updates of the Boards’ case law are provided by the "EPO Boards of Appeal Case Law" supplementary publications of the EPO Official Journal.

This book will be a useful reference work for anyone interested in European patent law. However, since a summary, no matter how carefully prepared, cannot serve as a substitute for the decision itself, readers should be aware that the texts of all decisions can be found in the decisions database of the Boards of Appeal website (www.epo.org/law-practice/case-law-appeals.html). The website also provides an RSS feed for users wishing to be alerted to newly published decisions or to information on the Boards of Appeal generally.

I would like to thank the members of our Legal Research Service, who updated and revised the text for the present ninth edition. My thanks also go to the EPO Language Service, without whose co-operation the simultaneous publication in the three official languages would not have been possible and to all the other EPO staff who contributed to the production of the book's latest version.

I am confident that this new edition will once again provide you, the reader, with an invaluable source of information for your work.