66.8

a) Subject to paragraph (b), when amending the description or the drawings, the applicant shall be required to submit a replacement sheet for every sheet of the international application which, on account of an amendment, differs from the sheet previously filed. The replacement sheet or sheets shall be accompanied by a letter which shall draw attention to the differences between the replaced sheets and the replacement sheets, shall indicate the basis for the amendment in the application as filed and shall preferably also explain the reasons for the amendment.

b) Where the amendment consists in the deletion of passages or in minor alterations or additions, the replacement sheet referred to in paragraph a) may be a copy of the relevant sheet of the international application containing the alterations or additions, provided that the clarity and direct reproducibility of that sheet are not adversely affected. To the extent that any amendment results in the cancellation of an entire sheet, that amendment shall be communicated in a letter which shall preferably also explain the reasons for the amendment.

c) When amending the claims, Rule 46.5 shall apply mutatis mutandis. The set of claims submitted under Rule 46.5 as applicable by virtue of this paragraph shall replace all the claims originally filed or previously amended under Articles 19 or 34, as the case may be.