The following deficiencies fall into this category:
Accordingly, the opposition is deficient if, for example, notice of opposition is submitted to the EPO belatedly, i.e. after expiry of the nine-month period, or where the opposition is notified within the opposition period but only verbally in a telephone call officially noted in the files. This category of deficiency also includes oppositions which, notwithstanding Art. 99(1), are filed with the central industrial property office of a Contracting State or an authority thereunder and not forwarded by these offices either at all or in time for them to be received by the EPO before the expiry of the opposition period. There is no legal obligation upon these offices or authorities to forward oppositions to the EPO.
Such a deficiency exists if the EPO is unable to identify the relevant patent on the basis of the particulars in the notice of opposition; for example, if only the proprietor of the contested patent and perhaps the title of the invention for which the patent was granted are mentioned in the notice of opposition. Such particulars alone are not an adequate description of the contested European patent, unless the proprietor of the patent who alone is named possesses only one patent or possesses several patents, the subject-matter of only one of which fits the title of the invention given in the notice of opposition, being clearly distinct from the subject-matter of the other patents which this proprietor holds. A mere indication of the number of the contested European patent in the notice of opposition constitutes sufficient identification of the patent concerned, provided that no conflicting information is given, e.g. an inconsistent name for the proprietor, and the conflict cannot be resolved from the information given.
Such a deficiency is present if it is not clear from the requisite statement whether the opposition is directed against the entire subject-matter of the patent or only a part of it, i.e. whether it is directed against all the claims or only against one or a part of one claim, such as an alternative or embodiment;
A notice of opposition contains such a deficiency if it does not mention at least one of the grounds for opposition referred to in Art. 100 (see D-III, 5). If non-patentability is given as a ground for opposition, the statement of grounds must at least implicitly indicate which conditions for patentability (Art. 52 to Art. 57) are considered not to have been fulfilled.
An opposition is adequately substantiated only if in respect of at least one of his grounds for opposition the opponent adduces facts, evidence and arguments establishing a possible obstacle to patentability under the EPC. He must indicate the technical context and the conclusions he has drawn from it. The content of the statement of grounds must be such as to enable the patent proprietor and the Opposition Division to examine the alleged ground for revocation without recourse to independent enquiries. Unsubstantiated assertions do not meet this requirement. Nor as a rule is mere reference to patent documents enough; unless the document is very short the opponent must indicate on which parts his opposition is based. Where there are allegations that use or oral description are comprised in the state of the art, the Opposition Division must be supplied with an indication of the facts, evidence and arguments necessary for determination of the matters set out under G-IV, 7.2 and G-IV, 7.3. See also in this respect T 328/87.
If, where there are multiple grounds for opposition, the facts, evidence and arguments for one ground are sufficiently indicated, the opposition is admissible, even if the facts, evidence and arguments in support of the other grounds for opposition are submitted belatedly. Such belated facts, evidence and arguments are in that event dealt with in accordance with E-V, 2.
It is immaterial, as far as the question of admissibility of an opposition is concerned, whether and to what extent the facts, evidence and arguments submitted in due time actually warrant revocation of the contested European patent or its maintenance in amended form. On the one hand, an unconvincing ground of opposition may have been clearly presented and argued (making the opposition admissible), whereas conversely a deficient submission may have been rejected as inadmissible even though, if properly drafted, it could have succeeded (see also T 222/85).
An indication of at least one ground of opposition and of the facts, evidence and arguments on which it is based fulfils the prerequisites for admissibility of the opposition in this respect. The evidence itself can also be produced after the expiry of the opposition period. Because of the long opposition period (9 months) it is however recommended, in order to expedite the opposition proceedings, that a single copy of any written evidence indicated in the notice of opposition be submitted as soon as possible and ideally with the notice of opposition.
Otherwise, if his opposition is admissible, the opponent will be invited to supply such evidence as soon as possible and as a rule within two months. If the documents thus requested are neither enclosed nor filed within the time limit set, the Opposition Division may decide not to take into account any arguments based on them. (As regards facts or evidence not submitted in due time and arguments presented at a late stage see E-V, 2 and E-II, 8.6.)