1.3.1 Gold standard: directly and unambiguously derivable

Any amendment to the parts of a European patent application or of a European patent relating to the disclosure (the description, claims and drawings) is subject to the mandatory prohibition on extension laid down in Art. 123(2) EPC and can therefore, irrespective of the context of the amendment made, only be made 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 these documents as filed (G 3/89, OJ 1993, 117; G 11/91, OJ 1993, 125; G 2/10, OJ 2012, 376, referring to this test as "gold standard"; confirmed for disclosed disclaimers in G 1/16, OJ 2018, A70; for undisclosed disclaimers, see however chapter II.E.1.7.2c)). After the amendment the skilled person may not be presented with new technical information (G 2/10).

In T 1937/17 the board held that, other than for the purposes envisaged in G 1/93 (OJ 1994, 541), a "technical contribution" was of no relevance when deciding on the allowability of amendments under Art. 123(2) EPC. Instead, the "gold standard" set out in G 2/10 was the only criterion that had to be applied.

Similarly, in T 768/20 the board rejected the argument made by the appellant (proprietor) that the "gold standard" concerned only amendments which provided a technical contribution. On the basis of a detailed analysis of the case law of the Enlarged Board, the board concluded that the "gold standard" developed in opinion G 3/89 and decision G 11/91, and reaffirmed by decision G 2/10, was the general rule to be used when examining the compliance of amendments with Art. 123(2) EPC. Undisclosed disclaimers constituted an exception to this rule. As confirmed in G 1/16, they were governed by the rules laid down in decision G 1/03. Point 2 of the Order of decision G 1/93 (and point 16 of the Reasons) also appeared to concern undisclosed disclaimers, which decision G 1/03 examined in greater detail. The board observed that the reasoning in G 1/03 was mainly based on the purpose of Art. 54(3) EPC and took the view that decision G 1/03 was best understood as specifying a limited set of exceptions, namely that, for the sake of consistency of the European patent system and similar teleological reasons, the requirements of Art. 123(2) EPC were deemed to be fulfilled even though the amendment did not meet the "gold standard". The board saw a confirmation for this view in G 2/10. To the best knowledge of the board, the case law of the Enlarged Board did not provide for any further exception in the context of Art. 123(2) EPC. This approach was followed in T 110/20.

As can be seen from the "gold standard", the assessment of the requirements of Art. 123(2) EPC is to be done from the standpoint of the skilled person (see chapter II.E.1.3.2 "Standpoint of the skilled person" below).

The subject-matter must be at least implicitly disclosed (T 860/00; see also G 2/10, OJ 2012, 376), see in this chapter II.E.1.3.3 "Implicit disclosure" below.

The boards have emphasised with regard to various tests developed for different cases of amendments that they are only meant to provide an indication of whether an amendment complies with Art. 123(2) EPC as interpreted according to the "gold standard". They may assist in determining the allowability of an amendment but do not take the place of the "gold standard" and should not lead to a different result.

In T 1535/23, T 1926/23 and T 435/24 the respective boards observed that the Court of Appeal of the Unified Patent Court in UPC_CoA_382/2024 applied the same test as the EPO to determine whether an amendment extended beyond the content of the application as filed, i.e. the "gold standard".