The composition of the Examining Division to which the request is referred must be as defined in Art. 18(2). This means that the Division must include three technical examiners; normally a legally qualified examiner will also be included. The main responsibility for dealing with the request up to the time of formulating the opinion is entrusted to one technical examiner, hereinafter referred to as the "primary examiner".

In order to guarantee that the opinion given is not influenced by earlier proceedings within the EPO on the application/patent in question, examiners who have taken part in such earlier proceedings as members of an Examining or Opposition Division should be excluded from the Examining Division set up under Art. 25. Where this is not practicable, the national court and the parties should be informed of the proposed members of the Examining Division under Art. 25 and of which among these members participated in European examination or opposition proceedings on the case. The court should be asked to state whether, in the circumstances, the request for a technical opinion is maintained.