The parts of the file which shall be excluded from inspection pursuant to Article 128, paragraph 4, shall be:
(a) the documents relating to the exclusion of or objections to members of the Boards of Appeal or of the Enlarged Board of Appeal;
(b) draft decisions and opinions, and all other documents, used for the preparation of decisions and opinions, which are not communicated to the parties;
(c) the designation of the inventor, if he has waived his right to be mentioned under Rule 18, paragraph 1;
(d) any other document excluded from inspection by the President of the European Patent Office on the ground that such inspection would not serve the purpose of informing the public about the European patent application or the resulting patent.