 In particular, prohibits adding subject-matter beyond the content of the application as filed, while prohibits an extension of the scope of protection by amendment after grant.Article 123(1) EPC provides the right for an applicant, in proceedings before the European Patent Office (EPO), to amend its European patent application and for a patent proprietor (during opposition proceedings) the right to amend its European patent.This must however be done in accordance with the Implementing Regulations, considering that the applicant is given "at least one opportunity to amend the application of his own volition."