T 0200/89 (Obvious error) of 07.12.1989

1. An allowable correction under Rule 88 EPC has a retrospective effect (Decisions J 4/85 - 3.1.1 dated 28 February 1986 "Correction of drawings/ETAT FRANCAIS", OJ EPO 1986, 205 and T 219/86 - 3.2.2 dated 3 July 1987 "Naming of opponent/ZOKOR", OJ EPO 1988, 254 followed), in contrast to an amendment under Article 123 EPC, which is not retrospective.

2. Article 123(3) EPC and Rule 88 EPC contain different requirements which are both intended to ensure legal certainty in the sense that after amendment or correction, to a skilled person, the protection conferred by the patent should not be greater than was apparent before the amendment or correction.

3. If, following approval of the text of a patent, the proprietor discovers an error in the text, he is not estopped from correcting the error under Rule 88 EPC.

4. For the purpose of Rule 88 EPC, whether an error is present in a document filed at the EPO is a subjective matter which may be established by reference to any relevant evidence (including here, the file history).

5. Whether correction of such an error in a patent is obvious in the sense of Rule 88 EPC is an objective matter which must be established by reference to the patent text in its entirety, but in isolation, and without reference to the file history.