In the opposition appeal proceedings underlying decision T 1839/18, the patent proprietor challenged the admissibility of the opposition. The patent proprietor argued, among other things, that the opponent had no legitimate interest in filing the opposition. In support, the proprietor referred to decision G 1/06 of the Enlarged Board of Appeal, which the proprietor interpreted as stipulating a general requirement for a “legitimate interest” in any procedural act taken before the EPO. The Board in T 1839/18 did not follow the proprietor’s interpretation. Rather, the Board emphasized that essentially any filed opposition was in the interest of the public by:
a) revoking undeserved monopolies or reducing them to the actually deserved scope;
b) fostering industrial development by preventing that innovation is led astray by wrongfully granted monopolies; and by:
c) enhancing legal certainty.
In the end, the Board found that the term straw man is in fact misguided, since no interest in filing an opposition has to be proven.
In conclusion the Board confirmed the established practice of filing an opposition at the behest of a third party, whose identity is not revealed, without indicating this fact to the EPO.