PCT International Search and Preliminary Examination Guidelines
PART VI THE INTERNATIONAL PRELIMINARY EXAMINATION STAGE (OTHER THAN THE INTERNATIONAL PRELIMINARY REPORT)
20.04 Any change, other than the rectification of obvious mistakes, in the claims, the description, or the drawings, including cancellation of claims, omission of passages in the description, or omission of certain drawings is considered an amendment. Any amendment to the international application must be submitted in the language in which the international preliminary examination is carried out.
20.05 The examiner need not take into account for the purposes of a written opinion or the international preliminary examination report any amendments, arguments or requests for rectification of obvious mistakes he receives after he has begun to draw up that opinion or report. The applicant may file an amendment to the description, the claims and the drawings in the prescribed manner, even if this is outside the time period set for reply in Rule 66.2(d). Since the examiner may begin to draw up the final report once the time period set for reply in Rule 66.2(d) expires, amendments filed after the expiration of the time period set in for reply in Rule 66.2(d) may or may not be considered. There may be situations where it is advisable, to the extent possible, to take such amendments or arguments into account, for example, where the international preliminary examination report has not yet been completed and it is readily apparent to the examiner that consideration of the late-filed response would result in the issuance of a favorable report.
20.06 Amendments to the description and the drawings must be made by filing replacement sheets when, on account of the amendments, the replacement sheet differs from the sheets previously filed. Amendments to the claims must be filed as a complete set to replace all the claims originally filed or previously amended under Articles 19 or 34, as the case may be. When amendments to the description, claims or drawings are made under Rule 66.8, the replacement sheets must 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 amendments in the application as filed and should preferably also explain the reasons for the amendments.
20.07 In the particular case where the amendments cancel passages in the description or certain drawings resulting in the cancellation of an entire sheet, the amendment must be submitted in the form of a letter canceling the sheet. That letter should preferably also explain the reasons for the amendments.
20.08 It should be noted that, when a replacement sheet or set of claims is required under paragraph 20.06, the applicant must submit such sheet in typed form. However, replacement sheets or sets of claims containing handwritten amendments may be allowed as well at the discretion of the examiner. In cases where the correction or amendment made by the applicant is minor, (for example, not more than six words), the International Preliminary Examining Authority may accept a copy of the relevant sheet or set of claims on which the correction or amendment is interlineated in typescript, if such interlineation is free from erasures, alterations and overwritings, and so long as the authenticity of this sheet is not in question and the requirements for clarity and good reproduction are met. The International Preliminary Examining Authority should invite the applicant to resubmit his amendments in proper form whenever compliance with these principles is lacking.