1.4.2 Basis in the application as originally filed – gold standard

The requirement of Art. 123(2) EPC as applied to the claims means that it is only permissible to delete features from an independent claim if there is a clear and unambiguous basis for a claim lacking these features in the application as originally filed (T 1726/06, referring to T 66/85, OJ 1989, 167, and T 558/13).

The board in T 755/12 pointed out that, although some tests such as the essentiality test (see in this chapter II.E.1.4.4 below) have been used as an aid in assessing the allowability of amendments, they could not replace the need to answer the question of what a skilled person would objectively have derived from the description, claims and drawings of a European patent application on the date of filing (G 3/89, OJ 1993, 117, see in this chapter II.E.1.3.1 "Gold standard: directly and unambiguously derivable" above). For further decisions highlighting that these tests are only tools and do not take the place of the "gold standard", see T 648/10, T 68/21 and the decisions cited in chapter II.E.1.4.4 b) and II.E.1.4.4 c).