217. If the receiving Office receives a sheet in response to an invitation to correct formal defects under Rule 26 and notices a discrepancy between the proposed replacement sheet and the sheet to be replaced, it proceeds as outlined in the following paragraphs.
218. If the discrepancy is in the request, the receiving Office may, after having obtained confirmation from the applicant, consider the proposed replacement sheet as constituting also a request for the rectification of an obvious mistake under Rules 91.1(b)(i) and 91.2. Where the receiving Office authorizes such rectification and that sheet complies with the formal requirements, the receiving Office marks that sheet “RECTIFIED SHEET (RULE 91)”; it notifies the applicant (Form PCT/RO/109) of the authorization of the rectification and sends a copy of that notification to the International Bureau and the International Searching Authority (Section 325(a)).
219. Where such discrepancy is on a sheet of any part of the international application other than the request, the receiving Office proceeds as outlined in paragraph 208(ii).
220. Where, following the invitation of the receiving Office, the applicant submits a request for rectification of an obvious mistake, and the International Searching Authority authorizes the rectification and sends to the receiving Office a copy of the sheet concerned marked “RECTIFIED SHEET (RULE 91)”, the receiving Office inserts that sheet into the home copy.
221. The procedure outlined in the preceding paragraphs also applies where the applicant submits a replacement sheet containing both a correction of a formal defect under Rule 26 and also a rectification of an obvious mistake, together with a request for rectification of the obvious mistake concerned.