In J 28/86 (OJ 1988, 85) the Legal Board of Appeal held that a request for examination filed by a person who was not entitled to act as a representative in accordance with Art. 134 EPC 1973 was invalid. The board noted that the situation did not change because the representative had later been entered on the list of professional representatives. In this capacity he had neither approved nor resubmitted the invalid request he had made earlier.

In T 665/89 the board addressed the question of the admissibility of an opposition by an opponent whose residence was not in a contracting state, where the notice of opposition was signed by a person who was neither a professional representative nor an employee of the opponent. The board of appeal concluded that the actions of the unauthorised person ought to be judged as if the signature were missing, and thus assumed that the deficiency was remediable. The opponent supplied the missing correct signature at the EPO's invitation within the time limit laid down. The document thus retained the original date of receipt in accordance with R. 36(3), third sentence, EPC 1973 (G 3/99 cites T 665/89).

R 18/09 the Enlarged Board of Appeal, referring in detail to G 3/99 (OJ 2002, 347), stated that concerning the principle that a plurality of persons acting in common be treated as a single party (a "group party") and the requirement that such a group party acts through a common representative which both apply to petition proceedings. It was also held in G 3/99 (point 20 of the Reasons) that there is no practical need to acknowledge the validity of procedural acts of one member of a group party who is not its common representative. Such a procedural act is treated by the EPO in the same way as a missing signature. Where an appeal is filed by a non-entitled person, it shall be considered as not duly signed and the common representative be invited to sign it within a given time limit. (See also G 3/99 under III.R.3. "Appointment of a common representative (R. 151 EPC)").

In J 32/86 the board held that the mere appointment of a professional representative to meet the requirement of Art. 133(2) EPC 1973 (the appellant had his residence in the USA) did not automatically have the legal effect of validating acts previously performed by an applicant himself. The EPO was however obliged to give the representative a fair chance to remedy any deficiency of this kind that might have occurred before his appointment and which could still lawfully be remedied by him.