Rule 79¹²¹
Preparation of the examination of the opposition

(1) The Opposition Division shall communicate the notice of opposition to the proprietor of the patent and shall give him them the opportunity to file his observations and to amend, where appropriate, the description, claims and drawings within a period to be specified.

(2) If several notices of opposition have been filed, the Opposition Division shall communicate them to the other opponents at the same time as the communication under paragraph 1.

(3) The Opposition Division shall communicate any observations and amendments filed by the proprietor of the patent to the other parties, and shall invite them, if it considers this expedient, to reply within a period to be specified. 

(4) In the case of an intervention under Article 105, the Opposition Division may dispense with the application of paragraphs 1 to 3.