Applicants not familiar with all the particularities of the European patent system are often surprised by the repeated requests of their European representatives to indicate support for the wording of every new or amended claim to be submitted to the European Patent Office (EPO). At the same time, strong feelings often overwhelm European patent attorneys when, during examination, they receive a pile of brand new claims from overseas colleagues with the cheerful remark that the claims have already been issued by their national patent office in a parallel application, together with instructions to file those claims at the EPO. This mutual "misunderstanding" has its roots in the provisions of the notorious Article 123 of the European Patent Convention (EPC), whose second paragraph requires that the subject matter is supported by the content of the original application, whereas the third paragraph prohibits the scope of protection of an issued patent being extended during opposition proceedings.
