hear and determine third-party challenges to the validity of European patents, in opposition proceedings). The EPO exists by virtue of the European Patent Convention (EPC), and is not legally bound to the European Union. To legally represent clients (generally patent applicants, proprietors and opponents) before the EPO, a patent attorney must first be registered to act in that capacity as a professional representative. To be registered, an individual must qualify as a European patent attorney and, to that end, must pass a written examination, the European Qualifying Examination (EQE). The EQE consists of four papers sat over three days, each day lasting between 5 hours and six and a half hours. Those who enroll for the examination must have an engineering or scientific degree (though long experience in a scientific domain can be sufficient under certain limited conditions), and the candidate must also have practiced under supervision for at least three years in the domain of national or European patent law. The EPC sets out the circumstances under which an applicant for a European patent must be represented by a professional representative in proceedings before the EPO. Typically, a representative is required if the patent applicant (or all of them if more than one) does not have a place of business in an EPC contracting state. Germany In Germany, only Patentanwälte/patent attorneys (or Rechtsanwälte/attorneys-at-Law, who are per se entitled to represent clients in all fields of law) are entitled to represent clients from abroad before the German Patent and Trade Mark Office (DPMA). German patent attorneys have done their university degrees in engineering or natural sciences and practised in industry before being accepted for an additional three years' education, i. e. completing legal training of 26 month with an established German patent attorney, at the same time studies of German Law and afterwards a training in intellectual property and an examination at the DPMA. They are further entitled to represent their clients before the German federal court of patents (and trademarks) and in patent cases (nullity) before the German Supreme Court. Hong Kong In Hong Kong, there is no regulation on the profession of patent attorneys or agents. The main reason is that Hong Kong does not have a standard patent (20 years) original grant system. Hong Kong recognizes standard patents or patents for invention registered and granted in the People's Republic of China, European Patent Office (designated UK), or