T 1621/16 - the Board of Appeal clarifies added matter assessment with respect to convergent lists

United Kingdom

In the recent appeal decision T 1621/16 concerning Proctor & Gamble's application EP 2264138, which relates to a hand dishwashing liquid, the Board of Appeal has provided greater clarity regarding the criteria for assessing added matter when convergent lists are used as basis for amendments.

The appellant (patentee) argued that the amended features of claim 1 were based on selections from lists of converging elements (i.e. lists of alternatives ranked in order of preference) and that such ‘selections’ should not be considered to be equivalent to selections from lists of non-converging elements (i.e. lists of mutually exclusive or partially overlapping elements). The appellant argued that since in a list of converging alternatives each of the more preferred alternatives is fully encompassed by all the less preferred and broader options in the list, selecting more or less preferred options did not lead to a singling out of an invention from among distinct alternatives but to more or less restricted versions of a single invention. The appellant also argued that selections from lists of converging alternatives could be considered analogous to deletions of elements from lists, which according to established case law (T 615/95, Reasons, points 4.3 and 6) represented a restriction of the scope of protection and were allowable under Article 123(2) EPC.

By contrast, the respondent (opponent) and opposition division considered that multiple selections involving intermediate elements (i.e. different from the most preferred) from a list of converging alternatives infringed Article 123(2) EPC because the convergence could only be considered to provide a specific pointer to the most preferred options. Lists of converging and non-converging alternatives should therefore be treated in a similar way

Ultimately, the Board of Appeal sided with the appellant and decided that multiple selections from convergent lists are permissible so long as certain criteria are fulfilled.

Selections from lists

In order to understand the significance of this decision, it is important to consider the background to this case. Amendments concerning lists can broadly be classified into three different categories: multiple selections from non-convergent lists, multiple selections from convergent lists, and deletions from lists.

In non-convergent lists, each element is distinct. In the absence of any pointer to that particular combination, the selection of elements from two non-convergent lists is considered to single out a combination not clearly and unambiguously derivable from the application and represents an extension of the content of the application as filed under Article 123(2) EPC. The EPO's application of this approach is largely uniform and there has been little or no divergence from this approach, which is often applied very strictly.

Deletion from lists may be allowable where lists are shrunk in such a way so as not to result in the singling out of a particular combination of features not originally disclosed in the application. In other words, the deletion must maintain the remaining subject matter as a generic group (for example, a generic group of compounds) and must not lead to a new invention having a previously undisclosed technical effect. This type of amendment is often seen in Markush formula claims, which are used to generically claim a group of chemical compounds that have similar structures and technical properties.

In regard to multiple selections from convergent lists, there has previously been very little clarity in the case law regarding whether such amendments should be treated in the same manner as selections from non-convergent lists or whether they are more analogous to deletions from lists. T 2273/10, cited in T 1621/16, stated that there was no basis in the application as filed for arbitrarily combining most preferred elements with less preferred elements taken from lists of converging alternatives, suggesting that convergent lists ought to be treated in the same manner as non-convergent lists. Likewise, in T 1150/15 the Board rejected the proprietor's combination of preferred options for certain substituents disclosed in the application as filed, since the mere preference of certain embodiments was not considered sufficient in the absence of basis in the application for the specific combination of features.

By contrast, T 2237/10, also cited in T 1621/16, considered that amendments based on combinations of most preferred and less preferred options selected from lists of converging alternatives could be allowable, but only when the features incorporated into the claim were derived from the original dependent claims rather than from the description.


In their decision, the Board clarified that selection from convergent lists is different in principal from selection from non-convergent lists, at least because the elements in a convergent list are not distinct features, but more-or-less restricted versions of the same feature. Thus, selecting one element from a list of converging alternatives does not lead to a singling out of an invention from among a plurality of distinct options, but simply to subject-matter based on a more or less restricted version of that feature.

The Board considered an analogy can therefore be drawn between selecting an element from a list of converging alternatives and deleting options from a list of non-converging alternatives, in the sense that both actions lead to a restriction of the scope of protection and not to a singling out of a specific invention from among different options.

The Board of Appeal emphasised, however, that selections from multiple convergent lists will not necessarily have basis. In order to satisfy the requirements of Article 123(2) EPC, the following criteria must also be met:

  • the subject-matter resulting from the multiple selections is not associated with an undisclosed technical contribution, and

  • the application as filed includes a pointer to the combination of features resulting from the multiple selections.

Application to novelty assessments

The EPO applies the same "disclosure" test (i.e. whether a disclosure is directly and unambiguously derivable) for the assessment of added matter/basis and novelty. This decision may therefore also impact the assessment of what is disclosed in a document for the purposes of novelty.

The criteria set out by the Board in this decision requires an assessment of whether there is a new undisclosed technical effect associated with the specific combination of elements. However, the assessment of technical effect (or technical contribution) is largely absent from the EPO's approach to assessing novelty, having been recently removed from the requirements for novelty of a selection invention, as is thought to more properly belong to the assessment of inventive step. It is therefore unclear whether this part of the test will also apply to assessing disclosure for documents relevant to novelty; this point therefore remains to be decided by future Boards.