If applicants reply in time to the invitation under Rule 63(1), indicating the subject-matter to be searched, and if a meaningful search based on the subject-matter that they have indicated is deemed possible by the search division, a search will be conducted on that subject-matter.[Rule 63(2); ]

If applicants reply to the invitation under Rule 63(1) but in their reply indicate subject-matter which it is still not possible to search in full, the search division will determine the subject-matter to search, but will do so in a way which is consistent with the applicant's response, to the extent that this is possible, or in exceptional cases may determine that no meaningful search is possible at all.

Statements consisting of reworded claims filed in reply to a communication pursuant to Rule 63 are not considered as amended claims in view of Rule 137(1) but merely as explanations in respect of the set of originally filed claims. These claims will then be formally introduced in the proceedings upon receipt by the EPO of a statement to that effect filed by the applicant within the time limits under Rule 70(1) and (2). This confirmatory statement can be filed either together with the reply to the extended European search report (Rules 70a(1) and Rule 70a(2)), or, where applicable, when complying with the requirements under Rule 70(1) and (2). As far as possible the search division will draw up the search report in the light of these clarifications. Both the search report and the search opinion must clearly indicate what has been searched.

If applicants reply in time to the invitation under Rule 63(1), they may, instead of indicating the subject-matter to be searched, simply argue why they believe that it is possible to carry out a meaningful search on all of the subject-matter claimed. If the search division is convinced by the applicant's argumentation, a full search report will be issued and the consequences of a limitation of the search which apply in examination will not ensue. If the search division is not convinced, or is only partially convinced, it will issue a partial search report and will determine which subject-matter to search or, in exceptional cases, will issue a declaration replacing the search report. The final responsibility as to whether an invitation under Rule 63 was appropriate lies with the examining division. An additional search may be necessary in examination after a declaration or a partial search report has been issued at the search stage following an invitation under Rule 63(1) (see C‑IV, 7.2).

Furthermore, the applicant may, in reply to an invitation under Rule 63, file arguments against the findings in the invitation requesting as a main request that the claims as filed be completely searched and as an auxiliary request, in the case that the search division is not convinced, indicate specific subject-matter to be searched (see also H‑III, 3.2).

A consultation may take place if the applicant phones the search division to enquire about the course of action after an invitation under Rule 63 has been sent. The consultation is limited to formal issues concerning the content of the invitation and the options available to the applicant. The search division writes minutes of the consultation, which are sent to the applicant (without time limit) for information only. The time limit set with the invitation is still applicable for the applicant to file a written reply; the consultation per se does not constitute a valid reply.