If the opposition division considers that the nature of the decision so requires, it is enlarged by the addition of a legally qualified examiner who has not taken part in the proceedings for grant.[Art. 19(2); ]

The principles established for inclusion of a legally qualified member and for consultation of the Directorate Patent Law, the department responsible for providing legally qualified members for examining and opposition divisions, by the examining division apply mutatis mutandis to the opposition division (see C‑VIII, 7). Difficult legal questions may also arise during the examination as to whether an opposition is to be rejected as inadmissible. In addition, consultation of a legally qualified member is to be envisaged in cases where it is questionable whether or not a disclosure by means other than a document was made available to the public.