2.3 Supplementary European search 

If a lack of unity of invention comes to light during a supplementary European search following an international (PCT) search, a partial supplementary European search report is drawn up on the invention or group of inventions first mentioned in the claims (see F‑V, 3.4) on which the supplementary European search was based (Rule 164(1)(a)), irrespective of the ISA's findings on unity of invention. Together with this partial search report, the applicant will be invited to pay a further search fee for each invention other than the one first mentioned in the claims (Rule 164(1)(b)), i.e. the same procedure is followed as for the non-unity invitation issued under Rule 64(1) for direct European patent applications (see B‑VII, 1.2). The applicant will also receive a provisional opinion on the patentability of the invention or unitary group of inventions first mentioned in the claims, which will include the reasons for the non-unity findings.