77. The international application must contain a title (Article 14(1)(a)(iii)). The title of the invention must be indicated twice, in Box No. I of the request and at the beginning of the first page of the description (Rules 4.1(a)(ii) and 5.1(a)). Both indications must be identical. Where the international application does not contain a title, the receiving Office invites (Form PCT/RO/106) the applicant to correct that defect under Rule 26 and sends a copy of the invitation to the International Bureau and also to the International Searching Authority (Rule 37). If the title appears in the request but not on the first page of the description, or vice versa, or the title as indicated on one of those pages contains a spelling mistake, the receiving Office may correct that defect ex officio (paragraphs 161 to 165). In all the other cases, the receiving Office invites (Form PCT/RO/106) the applicant to correct the title (paragraphs 153 to 155). It is not the responsibility of the receiving Office to check compliance of the title with Rule 4.3.