Administrative Instructions under the Patent Cooperation Treaty
Section 511
Rectifications of Obvious Mistakes under Rule 91
(a) Where the International Searching Authority authorizes a rectification under Rule 91, it shall:
(i) indelibly mark, in the upper right-hand corner of each replacement sheet, the international application number and the date on which that sheet was received;
(ii) indelibly mark, in the middle of the bottom margin of each replacement sheet, the words "RECTIFIED SHEET (RULE 91)" or their equivalent in the language of publication of the international application as well as an indication of the International Searching Authority as provided for in Section 107(b);
(iii) indelibly mark on the letter containing the rectification or accompanying any replacement sheet the date on which that letter was received;
(iv) keep in its files a copy of the letter containing the rectification or, when the rectification is contained in a replacement sheet, the replaced sheet, a copy of the letter accompanying the replacement sheet, and a copy of the replacement sheet;
(v) promptly transmit any letter and any replacement sheet to the International Bureau and a copy thereof to the receiving Office.
(b) Where the International Searching Authority refuses to authorize a rectification under Rule 91, it shall proceed as indicated under paragraph (a)(i), (iii) and (iv) and promptly transmit any letter and any proposed replacement sheet to the International Bureau.