The European Patent Convention has long required that the description of a European patent application be amended before grant to account for any developments that occur during examination of the application.
For example, applicants are often asked to acknowledge the prior art documents cited during examination in the background description of the application, or to amend any definitions of the “invention” in the description to correspond with the invention defined by the granted claims.
However, recent changes to the EPO’s Guidelines for Examination have placed an even greater emphasis on the requirement for the description of the patent application to be clear what is – and what is not – within the scope of the claimed invention.