Where the validity of the priority claim cannot be verified at the search stage (see B‑XI, 4), the basic reference date for the search must be taken as the date of filing of the European application as accorded by the Receiving Section. (For the reference date for the search with respect to conflicting applications, see, however, B‑VI, 3).[Art. 80; Rule 40; Art. 90(3); Art. 54(2); ]