The notice of opposition, filed in a written reasoned statement, must contain:
(i)the name, address and nationality of the opponent and the state in which the opponent's residence or principal place of business is located. Names of natural persons must be indicated by the person's family name and given name(s), the family name being indicated before the given name(s). Names of legal entities, as well as companies considered to be legal entities by reason of the legislation to which they are subject, must be indicated by their official designations. Addresses must be indicated in such a way as to satisfy the customary requirements for prompt postal delivery at the indicated address. They must comprise all the relevant administrative units, including the house number, if any. Opponents (whether natural or legal persons) whose residence or principal place of business is in an EPC contracting state and who act without a professional representative can use an address for correspondence other than their residence. The address for correspondence must be the opponent's own address. Post cannot be sent to a different (natural or legal) person, since that requires a valid form of representation under Art. 133 and Art. 134. It is recommended that the telephone and fax numbers be indicated (see D‑IV, 22.214.171.124(i) and D‑IV, 1.4.2);
(iii)a statement of the extent to which the European patent is opposed and of the grounds on which the opposition is based as well as an indication of the facts and evidence presented in support of these grounds (see D‑IV, 126.96.36.199(iii) to D‑IV, 188.8.131.52(v) and D‑IV, 1.4.2). The requirement under Rule 76(1) that notice of opposition must be filed in a written reasoned statement also implies presenting arguments. However, in order to streamline opposition procedure, it is recommended that a single copy of any written evidence be submitted as soon as possible and ideally with the notice of opposition (see D‑IV, 184.108.40.206(v), last two paragraphs);
(iv)if the opponent has appointed a representative, the representative's name and address of place of business in accordance with the provisions of subparagraph (i) as set out above (see D‑IV, 220.127.116.11(iii) and D‑IV, 1.4.2).
D‑IV, 1 sets out further details and explains how to deal with the opposition if one of these requirements is not fulfilled.