The decisions below are mainly about applying R. 88 EPC 1973, which however has not substantively changed; in R. 139 EPC, only minor editorial amendments to all three language versions have been made.

In G 2/95 (OJ 1996, 555) the Enlarged Board held that the complete documents forming a European patent application, that is the description, claims and drawings, cannot be replaced by way of a correction under R. 88 EPC 1973 by other documents which the applicants had intended to file with their request for grant (overruling T 726/93, OJ 1995, 478). The interpretation of R. 88 EPC 1973 had to be in accord with Art. 123(2) EPC 1973. This meant that a correction under R. 88 EPC 1973 was thus bound by Art. 123(2) EPC 1973, in so far as it related to the content of the European patent application as filed (see G 3/89 (OJ 1993, 117). Such a correction could therefore be made only within the limits of what a skilled person would derive directly and unambiguously, using common general knowledge and seen objectively and relative to the date of filing, from the whole of the documents forming the content of the European patent application (referring to G 3/89).

The content of the European patent application was formed by the parts of the application which determined the disclosure of the invention, namely the description, claims and drawings (referring to G 3/89). As a result of the prohibition of extension under Art. 123(2) EPC 1973, documents other than the description, claims and drawings could only be used in so far as they were sufficient for proving the common general knowledge on the date of filing (referring to G 3/89). On the other hand, documents not meeting this condition could not be used for a correction even if they were filed together with the European patent application. These included, inter alia, priority documents, the abstract and the like (referring to G 3/89). See also J 5/06.

In decision J 21/94 of 20 January 1997 date: 1997-01-20 and terminating the appeal proceedings following the referral to the Enlarged Board of Appeal dealt with in G 2/95 (OJ 1996, 555), the Legal Board concluded that the originally disclosed invention B could be accorded a filing date even if there were contradictions between the request for grant (which related to invention A) and the application documents (which disclosed invention B). If a further invention (here invention A) was disclosed during grant proceedings, it could not be given a filing date unless it was clear that protection for this invention was now sought.

In J 5/06, the board referred to J 21/94 date: 1997-01-20 and stated, if an application is accorded a date of filing pursuant to Art. 80 EPC 1973, the technical content of the application is definitively established (G 2/95). Exchanging this technical content with another one is a technical modification. The application of the strict requirements of either Art. 123(2) or R. 88 EPC 1973, second sentence, is not limited to those circumstances when a minor part of a complete description needs to be interpreted relative to the rest, but these requirements are applicable to any suggested amendment or correction. This means that the technical content of the application as filed cannot simply be discarded, even if it does not correspond to the intention of the applicant, but must be considered when deciding whether an amendment or correction is allowable or not. The intention of the applicant at the time of filing (or even later) is immaterial in establishing the technical content of a patent application.

In J 16/13 the appellant requested correction of the wrongly filed description and claims under R. 139 EPC. The board stated that the skilled person would have immediately recognised the mismatch between the drawings and the other parts of the description. However, it was not "immediately evident that nothing else would have been intended than what is offered as the correction". R. 139 EPC required certainty as to the only correction possible; here, that was lacking. The board noted that the case before it was similar to J 5/06, in which it had been confirmed that the earlier case law (up to T 726/93) holding that R. 88 EPC 1973 had to be applied in the light of the applicant's intentions had clearly now been overturned (see G 2/95, J 21/94 date: 1997-01-20, G 3/89), and the request that the patent specification be corrected under R. 139 EPC was refused.