T 0401/88 (Test piece) of 28.02.1989

A requested amendment which represents an inadmissible extension within the meaning of Article 123(2) EPC cannot be allowed as a correction under Rule 88, second sentence, EPC. An error may be corrected only if a skilled person would regard the correction as necessarily implied by the contents of the documents as originally filed - in the same way as when the admissibility of an amendment under Article 123(2) EPC is assessed. This follows both from Article 138(1)(c) EPC, under which a European patent is revoked if its subject-matter extends beyond the content of the application as filed, and from Article 164(2) EPC, which stipulates that the provisions of the Convention take precedence over those of the Implementing Regulations (see point 2.2 of the Reasons and T 13/83 - 3.3.1 "Polyisocyanurate/ICI Americas, 13 April 1984, OJ EPO 1984, 428).