3. No meaningful search possible
3.4 Applications falling under Rule 63 and lacking unity
There are cases where the application not only falls so short of the EPC requirements that it is impossible to carry out a meaningful search into the state of the art based on some of the subject-matter claimed (B‑VIII, 1, B-VIII, 2 and B-VIII, 3) but also lacks unity of invention under Art. 82 and Rule 44. Sometimes it is enough for the search division to raise only unity of invention and send an invitation under Rule 64(1) (see B‑VII, 1.1 and B-VII, 1.2), for example where a large number of claims results in a serious lack of conciseness but this can be resolved by splitting the claims up into the different inventions.
In other cases, however, the search division may need to apply the procedures under both Rule 64(1) (i.e. invite the applicant to pay further search fees for inventions other than the one first mentioned in the claims) and Rule 63(1) (i.e. invite the applicant to indicate the subject-matter to be searched). If so, it will send the applicant the Rule 63(1) invitation first. Where the lack of unity is already apparent, this invitation will also identify the invention (or group of inventions) first mentioned in the claims ("first invention" ‒ see F‑V, 3.4) and the claims which relate to it, either in full or in part, and ask the applicant to clarify what to search in this respect.
If the applicant has not replied by expiry of the time limit under Rule 63(1), any subject-matter to be searched for the first invention will be determined according to the procedures described in B‑VIII, 3.2. A partial search report (or exceptionally a declaration of no search) will then be drawn up on this first invention and sent to the applicant, along with an invitation to pay further search fees under Rule 64(1) for the other inventions and a provisional opinion on the first invention's patentability that includes the reasons for the non-unity findings. Where appropriate, the invitation under Rule 64(1) may also include an invitation under Rule 63(1) asking the applicant to clarify the subject-matter to be searched for any other inventions for which they later pay further search fees.
Where these exceptional circumstances arise in cases of supplementary European search reports for Euro-PCT applications, the procedure is the same, except that a Rule 164(1) invitation is sent instead of a Rule 64 invitation.
Rule 63 also applies to searches performed under Rule 164(2) (see C‑III, 3.1). As for searches on directly filed European patent applications, any Rule 63 objection relating to an invention for which a search fee has to be paid must be included in the invitation to pay that fee.